Solid state lighting devices including quantum confined semiconductor nanoparticles, an optical component for a solid state lighting device, and methods

ABSTRACT

A solid state lighting device including a light source capable of emitting white light including a blue spectral component and having a deficiency in a spectral region, and an optical component that is positioned to receive at least a portion of the light generated by the light source, the optical component comprising an optical material for converting at least a portion of the blue spectral component of the light to one or more predetermined wavelengths such that light emitted by the solid state lighting device includes light emission from the light source supplemented with light emission at one or more predetermined wavelengths, wherein the optical material comprises quantum confined semiconductor nanoparticles. Also disclosed is lighting fixture, a cover plate for a lighting fixture and a method.

This application is a continuation of commonly owned InternationalApplication No. PCT/US2009/002789 filed 6 May 2009, which was publishedin the English language as PCT Publication No. WO2009/151515 on 17 Dec.2009, which International Application claims priority to U.S.Application No. 61/050,929, filed 6 May 2008, U.S. Application No.61/162,293, filed 21 Mar. 2009, U.S. Application No. 61/173,375 filed 28Apr. 2009, and U.S. Application No. 61/175,430 filed 4 May 2009, each ofthe foregoing hereby being incorporated herein by reference in itsentirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the technical field of solid statelighting devices including nanoparticles, lighting fixtures andcomponents including nanoparticles, and methods.

SUMMARY OF THE INVENTION

The present invention relates to a solid state lighting device includinga light source and an optical component that is positioned to receive atleast a portion of light emitted from the light source, such that theoptical component converts a portion of the light received by theoptical component to one or more predetermined wavelengths to alter atleast one characteristic of light output emitted from the device. Thepresent invention also relates to lighting fixtures and componentsincluding an optical material to convert at least a portion of lightemitted from a light source. The present invention also relates tomethods for improving the lumens per watt efficiency of a solid statelighting device.

In accordance with one aspect of the present invention, there isprovided a solid state lighting device comprising a light source capableof emitting white light including a blue spectral component and having adeficiency in a spectral region, and an optical component that ispositioned to receive at least a portion of the light generated by thelight source, the optical component comprising an optical material forconverting at least a portion of the blue spectral component of thelight to one or more predetermined wavelengths such that light emittedby the solid state lighting device includes light emission from thelight source supplemented with light emission at one or morepredetermined wavelengths, wherein the optical material comprisesquantum confined semiconductor nanoparticles.

In certain preferred embodiments, the predetermined wavelength isselected to meet or compensate for the deficiency, in the spectralregion of the light source. In certain embodiments, for example, wherethe light source emits white light with a spectral deficiency in the redspectral region, the predetermined wavelength can be in a range fromabout 575 nm to about 650 nm, from about 580 nm to about 630 nm, fromabout 590 nm to about 630 nm, from about 590 nm to about 630 nm, or fromabout 600 nm to about 620 nm. In certain embodiments, the wavelength isabout 616 nm.

In certain embodiments, for example, where the light source has aspectral deficiency in the cyan spectral region, the predeterminedwavelength can be in a range from about 450 nm to about 500 nm.

In certain embodiments, for example, where the light source emits whitelight with one or more spectral deficiencies, the optical component cancomprise an optical material including one or more different types ofquantum confined semiconductor nanoparticles (based on composition,structure and/or size), wherein each different type of quantum confinedsemiconductor nanoparticle can convert a portion of the blue spectralcomponent of the light to a predetermined wavelength that is differentfrom the predetermined wavelength emitted by at least one of any othertype of quantum confined semiconductor nanoparticles included in theoptical material.

In embodiments including two or more different types of quantum confinedsemiconductor nanoparticles that emit at different predeterminedwavelengths, the different types of quantum confined semiconductornanoparticles can be included in one or more different opticalmaterials. In certain embodiments, different types of quantum confinedsemiconductor nanocrystals can be included in separate opticalmaterials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical components in a stacked arrangement. In such embodiments, eachoptical component can include one or more optical materials as describedabove.

In embodiments including two or more different types of quantum confinedsemiconductor nanoparticles that emit at different predeterminedwavelengths, light emitted by the solid state lighting device includeslight emission that is supplemented with light emission at such two ormore different predetermined wavelengths. In such case, the two or moredifferent predetermined wavelengths are selected to meet or compensatefor one or more of the spectral deficiencies of the light source.

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alsoincrease the General Color Rendering Index (R_(a)) of light output fromthe light source. For example, in certain embodiments, the opticalcomponent can increase the General Color Rendering Index (R_(a)) oflight output from the light source by at least 10%. In certainembodiments, the General Color Rendering Index (R_(a)) is increased to apredetermined General Color Rendering Index (R_(a)).

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alter thecorrelated color temperature (CCT) of light output from the lightsource. In certain embodiments, the optical component can lower thecorrelated color temperature of light output from the light source by,for example, at least about 1000K; at least about 2000K, at least 3000K,at least 4000K, etc.

In certain preferred embodiments, the lumens per watt efficiency of thelight source is not substantially affected by alteration of the CCTthrough use of the optical component.

In certain embodiments, the CCT is altered to a predetermined CCT.

In certain preferred embodiments, quantum confined semiconductornanoparticles comprise semiconductor nanocrystals.

In certain embodiments, the quantum confined semiconductor nanoparticleshave a solid state quantum efficiency of at least 40%. In certainembodiments, the quantum confined semiconductor nanoparticles have asolid state quantum efficiency of at least 50%. In certain embodiments,the quantum confined semiconductor nanoparticles have a solid statequantum efficiency of at least 60%.

In certain embodiments, the quantum confined semiconductor nanoparticlesmaintain at least 40% efficiency during operation of the solid statelight emitting device.

In certain preferred embodiments, the optical material comprises quantumconfined semiconductor nanoparticles capable of emitting red light.

In certain embodiments, for example, the light emitted by the lightsource has a General Color Rendering Index (R_(a)) less than 80. Incertain embodiments, the light emitted by the solid state lightingdevice has a General Color Rendering Index (R_(a)) greater than 80. Incertain embodiments, the light emitted by the solid state lightingdevice has a General Color Rendering Index (R_(a)) greater than 85. Incertain embodiments, the light emitted by the solid state lightingdevice has a General Color Rendering Index (R_(a)) greater than 90. Incertain embodiments, the light emitted by the solid state lightingdevice has a General Color Rendering Index (R_(a)) greater than 95. Incertain embodiments, the General Color Rendering Index (R_(a)) of thelight emitted by the solid state lighting device is at least 10% higherthan the General Color Rendering Index (R_(a)) of the light emitted bythe light source.

In certain embodiments, light emitted from the solid state lightingdevice has a correlated color temperature that is at least about 1000Kless than that of light emitted from the light source.

In certain embodiments, light emitted from the solid state lightingdevice has a correlated color temperature that is at least about 2000Kless than that of light emitted from the light source.

In certain embodiments, light emitted from the solid state lightingdevice has a correlated color temperature that is at least about 3000Kless than that of light emitted from the light source.

In certain embodiments, light emitted from the solid state lightingdevice has a correlated color temperature that is at least about 4000Kless than that of light emitted from the light source.

In certain embodiments, the solid state lighting device maintainsgreater than 70% of the light source lumens per watt efficiency. Incertain embodiments, the solid state lighting device maintains greaterthan 80% of the light source lumens per watt efficiency. In certainembodiments, the solid state lighting device maintains greater than 90%of the light source lumens per watt efficiency. In certain embodiments,the solid state lighting device maintains greater than 100% of the lightsource lumens per watt efficiency. In certain embodiments, the solidstate lighting device maintains greater than 110% of the light sourcelumens per watt efficiency.

In certain embodiments, the lumens per watt efficiency of the solidstate lighting device does not substantially vary as a function of thecolor temperature of the solid state lighting device.

In certain embodiments, the optical material further comprises a hostmaterial in which the quantum confined semiconductor nanoparticles aredistributed. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 0.001 to about 5 weight percent of the weight of thehost material. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 0.5 to about 3 weight percent of the weight of the hostmaterial. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 1 to about 3 weight percent of the weight of the hostmaterial. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 1 to about 2 weight percent of the weight of the hostmaterial.

In certain embodiments, the optical material further comprises lightscatterers. In certain embodiments, the light scatterers comprise lightscattering particles. In certain embodiments, light scattering particlesare included in the optical material in an amount in a range from about0.001 to about 5 weight percent of the weight of the host material. Incertain embodiments, light scattering particles are included in theoptical material in an amount in a range from about 0.5 to about 3weight percent of the weight of the host material. In certainembodiments, light scattering particles are included in the opticalmaterial in an amount in a range from about 1 to about 3 weight percentof the weight of the host material. In certain embodiments, lightscattering particles are included in the optical material in an amountin a range from about 1 to about 2 weight percent of the weight of thehost material.

In certain embodiments, an optical component further includes a supportelement. Preferably, the support element is optically transparent tolight emitted from the light source and to light emitted from thenanoparticles.

In certain embodiments, the support element can include other optionallayers.

In certain embodiments, the support element can include other optionalfeatures.

In certain embodiments, the optical material is at least partiallyencapsulated.

In certain embodiments, the optical material is fully encapsulated.

In certain embodiments, an optical component including a support elementcan serve as a cover plate for the solid state lighting device.

In certain embodiments, the support element comprises a light diffusercomponent of the solid state lighting device.

In certain embodiments, the support element is rigid.

In certain embodiments, the support element is flexible.

In certain embodiments, the optical material comprising quantum confinedsemiconductor nanoparticles is disposed over a surface of a supportelement. Preferably, the optical material is disposed over a majorsurface of the support element. Preferably, the optical material isdisposed over a surface of the support element facing the light source.

In certain embodiments, the optical material is disposed as one or morelayers over a predetermined area of a surface of the support element.

In certain embodiments, the layer comprises an optical material thatfurther includes a host material in which the quantum confinedsemiconductor nanoparticles are distributed. In certain embodiments, thelayer includes from about 0.001 to about 5 weight percent quantumconfined semiconductor nanoparticles based on the weight of the hostmaterial. In certain embodiments, the layer further comprises lightscatterers. In certain embodiments, light scatterers are included in thelayer in an amount in the range from about 0.001 to about 5 weightpercent of the weight of the host material.

In certain embodiments, a layer including optical material including ahost material has a thickness, for example, from about 0.1 micron toabout 1 cm. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 0.1 to about 200microns. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 10 to about 200microns. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 30 to about 80microns.

In certain preferred embodiments, the optical material is not in directcontact with the light source.

In certain preferred embodiments, the optical component is not in directcontact with the light source.

In certain preferred embodiments, the temperature at the location of thenanoparticles in the solid state light emitting device during operationis 90° C. or less.

In certain preferred embodiments, the temperature at the location of thenanoparticles in the solid state light emitting device during operationis 75° C. or less.

In certain preferred embodiments, the temperature at the location of thenanoparticles in the solid state light emitting device during operationis 60° C. or less.

In certain preferred embodiments, the temperature at the location of thenanoparticles in the solid state light emitting device during operationis 50° C. or less.

In certain preferred embodiments, the temperature at the location of thenanoparticles in the solid state light emitting device during operationis 40° C. or less.

In certain more preferred embodiments, the temperature at the locationof the nanoparticles in the solid state light emitting device duringoperation is in a range from about 30° C. to about 60° C.

In certain embodiments, the light source comprises a white lightemitting device. (A light emitting device is also referred to herein asan “LED”).

In certain preferred embodiments, the white light emitting LED comprisesa blue light emitting semiconductor LED including a phosphor materialfor converting the blue LED light output to white light. In certainembodiments, optical material can comprise quantum confinedsemiconductor nanoparticles capable of emitting light in the orange tored spectral (e.g., from about 575 nm to about 650 nm) region. Incertain embodiments, optical material can comprise quantum confinedsemiconductor nanoparticles capable of emitting light in the redspectral region. In certain embodiments, optical material can comprisequantum confined semiconductor nanoparticles capable of emitting lightin the orange spectral region. In certain embodiments, optical materialcan comprise quantum confined semiconductor nanoparticles capable ofemitting light in the cyan spectral region. In certain embodiments,optical material can comprise quantum confined semiconductornanoparticles capable of emitting light in one or more other spectralregions in which the light source has a deficiency.

In certain embodiments, the white light emitting LED comprises a UVlight emitting semiconductor LED including a phosphor material forconverting the UV LED light output to white light. In certainembodiments, optical material can comprise quantum confinedsemiconductor nanoparticles capable of emitting light in the orange tored spectral (e.g., from about 575 nm to about 650 nm) region. Incertain embodiments, optical material can comprise quantum confinedsemiconductor nanoparticles capable of emitting light in the redspectral region. In certain embodiments, optical material can comprisequantum confined semiconductor nanoparticles capable of emitting lightin the cyan spectral region. In certain embodiments, optical materialcan comprise quantum confined semiconductor nanoparticles capable ofemitting light in the orange spectral region. In certain embodiments,optical material can comprise quantum confined semiconductornanoparticles capable of emitting light in one or more other spectralregions in which the light source has a deficiency.

In certain embodiments, a solid state lighting device comprises a lightsource comprising an LED capable of emitting white light includingemission in the blue spectral region and having a deficiency in the redspectral region; and an optical component that is positioned to receivelight emitted by the LED, the optical component comprising an opticalmaterial for converting at least a portion of the emission in the bluespectral region to light in the red spectral region with a wavelength ina range from about 600 nm to about 620 nm such that light emitted by thesolid state lighting device includes white light emission from the LEDlight source supplemented with light emission in the red spectralregion, wherein the optical material comprises quantum confinedsemiconductor nanoparticles.

In certain embodiments, a solid state lighting device comprises a lightsource comprising an LED capable of emitting white light includingemission in the blue spectral region and having a deficiency in theorange to red spectral region; and an optical component that ispositioned to receive light emitted by the LED, the optical componentcomprising an optical material for converting at least a portion of theemission in the blue spectral region to light in the spectral regionfrom about 575 nm to about 650 nm such that light emitted by the solidstate lighting device includes white light emission from the LED lightsource supplemented with light emission in the spectral region fromabout 575 nm to about 650 nm, wherein the optical material comprisesquantum confined semiconductor nanoparticles. In certain embodiments,for example, the optical material can convert at least a portion of theblue spectral emission to light in the spectral region from about 575 nmto about 650 nm, from about 580 to about 630 nm, from about 590 nm toabout 630 nm, from about 600 nm to about 620 nm, etc. In certainembodiments, the wavelength can be about 616 nm.

In certain embodiments, at least 10% of the emission in the bluespectral region is converted by the quantum confined semiconductornanoparticles.

In certain embodiments, at least 30% of the emission in the bluespectral region is converted by the quantum confined semiconductornanoparticles.

In certain embodiments, at least 60% of the emission in the bluespectral region is converted by the quantum confined semiconductornanoparticles.

In certain embodiments, at least 90% of the emission in the bluespectral region is converted by the quantum confined semiconductornanoparticles.

In certain embodiments, from about 50% to about 75% of the emission inthe blue spectral region is converted by the quantum confinedsemiconductor nanoparticles.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material are cadmium free.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material comprise a III-V semiconductor material.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material comprise a semiconductor nanocrystalincluding a core comprising a semiconductor material and an inorganicshell disposed on at least a portion of a surface of the core.

In accordance with another aspect of the present invention, there isprovided an endoscopy light source comprising a solid state lightingdevice taught herein.

In accordance with another aspect of the present invention, there isprovided an endoscopy light source comprising an optical componenttaught herein.

In accordance with another aspect of the present invention, there isprovided an optical component useful with a light source that emitswhite light including a blue spectral component and at least onespectral deficiency in another region of the spectrum, the opticalcomponent comprising an optical material for converting at least aportion of the blue spectral component of light output from the lightsource to one or more different predetermined wavelengths, wherein theoptical material comprises quantum confined semiconductor nanoparticles.

In certain preferred embodiments, the predetermined wavelength isselected to meet or compensate for at least one of the spectraldeficiencies of the light source, for example, by supplementing thelight output of the light source in at least one of the spectraldeficiency regions.

In certain embodiments, for example, where the light source emits whitelight with a spectral deficiency in the red spectral region, thepredetermined wavelength can be in a range from about 575 nm to about650 nm, from about 580 nm to about 630 nm, from about 590 nm to about630 nm, from about 600 nm to 620 nm, etc. In certain preferredembodiments, the wavelength is about 616 nm.

In certain more preferred embodiments, the optical material includes oneor more different types of quantum confined semiconductor nanoparticleswherein the different types can emit at one or more differentpredetermined wavelengths to compensate for one or more spectraldeficiencies of the light output from the light source.

In certain embodiments, for example, where the light source emits whitelight with a spectral deficiency in the cyan spectral region, thepredetermined wavelength can be in a range from about 450 nm to about500 nm.

In certain embodiments, the optical component includes an opticalmaterial comprising one or more different types of quantum confinedsemiconductor nanoparticles (based on composition, structure and/orsize), wherein each different type of quantum confined semiconductornanoparticles emits light at predetermined wavelength that can be thesame or different from the predetermined wavelength emitted any othertype of quantum confined semiconductor nanoparticles included in theoptical material, and wherein one or more different predeterminedwavelengths are selected such that the optical material will compensatefor one or more spectral deficiencies of the intended light source. Incertain embodiments including two or more different types of quantumconfined semiconductor nanoparticles, at least two of the types arecapable of emitting light at a predetermined wavelength that isdifferent from that emitted by other types of quantum confinedsemiconductor nanoparticles that may be included in the opticalcomponent.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alsoincrease the General Color Rendering Index (R_(a)) of light output fromthe light source. For example, in certain embodiments, the opticalcomponent can increase the General Color Rendering Index (R_(a)) oflight output from the light source by at least 10%. In certainembodiments, the General Color Rendering Index (R_(a)) is increased to apredetermined General Color Rendering Index (R_(a)).

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alter thecorrelated color temperature (CCT) of light output from the lightsource. In certain embodiments, the optical component can lower thecorrelated color temperature of light output from the light source by,for example, at least about 1000K; at least about 2000K, at least 3000K,at least 4000K, etc.

In certain embodiments, the lumens per watt efficiency of the lightsource is not substantially affected by alteration of the CCT throughuse of the optical component.

In certain embodiments, the CCT is altered to a predetermined CCT.

In certain preferred embodiments, quantum confined semiconductornanoparticles comprise semiconductor nanocrystals.

In certain embodiments, the quantum confined semiconductor nanoparticleshave a solid state quantum efficiency of at least 40%. In certainembodiments, the quantum confined semiconductor nanoparticles have asolid state quantum efficiency of at least 50%. In certain embodiments,the quantum confined semiconductor nanoparticles have a solid statequantum efficiency of at least 60%.

In certain embodiments, the quantum confined semiconductor nanoparticlesmaintain at least 40% efficiency during use of the optical component.

In certain preferred embodiments, the optical material comprises quantumconfined semiconductor nanoparticles capable of emitting red light. Inother certain preferred embodiments, the optical material comprisesquantum confined semiconductor nanoparticles capable of emitting lightin the orange to red spectral region.

In certain embodiments, the optical material further comprises a hostmaterial in which the quantum confined semiconductor nanoparticles aredistributed. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 0.001 to about 5 weight percent of the weight of thehost material. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 0.5 to about 3 weight percent of the weight of the hostmaterial. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 1 to about 3 weight percent of the weight of the hostmaterial. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 1 to about 2 weight percent of the weight of the hostmaterial.

In certain embodiments, the optical material further comprises lightscatterers.

In certain embodiments, the light scatterers comprise light scatteringparticles. In certain embodiments, light scattering particles areincluded in the optical material in an amount in a range from about0.001 to about 5 weight percent of the weight of the host material. Incertain embodiments, light scattering particles are included in theoptical material in an amount in a range from about 0.5 to about 3weight percent of the weight of the host material. In certainembodiments, light scattering particles are included in the opticalmaterial in an amount in a range from about 1 to about 3 weight percentof the weight of the host material. In certain embodiments, lightscattering particles are included in the optical material in an amountin a range from about 1 to about 2 weight percent of the weight of thehost material.

In certain embodiments, an optical component further includes a supportelement. Preferably, the support element is optically transparent tolight emitted from the light source and to light emitted from thenanoparticles.

In certain embodiments, an optical component including a support elementcan serve as a cover plate for the solid state lighting device.

In certain embodiments, the support element comprises a light diffusercomponent of the solid state lighting device.

In certain embodiments, the support element is rigid.

In certain embodiments, the support element is flexible.

In certain embodiments, the optical material comprising quantum confinedsemiconductor nanoparticles is disposed over a surface of a supportelement. Preferably, the optical material is disposed over a surface ofthe support element facing the light source.

In certain embodiments, the optical material is disposed as one or morelayers over a predetermined area of the surface of the support element.

In certain embodiments, the layer comprises an optical material thatfurther includes a host material in which the quantum confinedsemiconductor nanoparticles are distributed. In certain embodiments, thelayer includes from about 0.001 to about 5 weight percent quantumconfined semiconductor nanoparticles based on the weight of the hostmaterial. In certain embodiments, the layer further comprises lightscatterers. In certain embodiments, light scatterers are included in thelayer in an amount in the range from about 0.001 to about 5 weightpercent of the weight of the host material.

In certain embodiments, a layer including optical material including ahost material has a thickness, for example, from about 0.1 micron toabout 1 cm. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 0.1 to about 200microns. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 10 to about 200microns. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 30 to about 80microns.

In certain embodiments, the optical component can convert at least 10%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert at least 30%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert at least 60%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert at least 90%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert from about 50%to about 75% of the emission in the blue spectral region to one or morepredetermined wavelengths.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material are cadmium free.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material comprise a III-V semiconductor material.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material comprise a semiconductor nanocrystalincluding a core comprising a semiconductor material and an inorganicshell disposed on at least a portion of a surface of the core.

In certain embodiments, the optical material is at least partiallyencapsulated.

In certain embodiments, the optical material is fully encapsulated.

In accordance with another aspect of the present invention, there isprovided a lighting fixture adapted to receive a solid statesemiconductor light emitting device, wherein the fixture includes anoptical component that is positioned in the fixture relative to theposition for the light source such that at least a portion of the lightgenerated by the light source passes into the optical component beforebeing emitted from the fixture, wherein the optical component comprisesan optical material capable of converting light having a firstpredetermined wavelength into light having a one or more differentpredetermined wavelengths in order to supplement the spectrum of thelight emitted from the light source, and wherein the optical componentcomprises an optical material comprising quantum confined semiconductornanoparticles.

In certain embodiments, the optical component is capable of converting afirst predetermined wavelength in the blue spectral region into one ormore different predetermined wavelengths in one or more spectral regionsin which the light source has a deficiency.

In certain embodiments, for example, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the orange tored spectral region. In certain embodiments, the optical component iscapable of converting a first predetermined wavelength in the bluespectral region into one or more different predetermined wavelengths inthe red spectral region. In certain embodiments, the optical componentis capable of converting a first predetermined wavelength in the bluespectral region into one or more different predetermined wavelengths inthe cyan spectral region. In certain embodiments, the optical componentis capable of converting a first predetermined wavelength in the bluespectral region into one or more different predetermined wavelengths inthe red spectral region and one or more different predeterminedwavelengths in the orange spectral region. In certain embodiments, forexample, where a first predetermined wavelength is to be converted intomore one or more different predetermined wavelengths, the opticalmaterial comprises one or more different types of quantum confinedsemiconductor nanoparticles (based on composition, structure and/orsize), wherein each different type of quantum confined semiconductornanoparticle can convert a portion of the first predetermined wavelengthto one or more different predetermined wavelengths. In such case, one ormore different predetermined wavelengths are selected to meet orcompensate for one or more of the spectral deficiencies of the lightsource for which the cover plate in intended for use.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In certain embodiments, the optical material further comprises a hostmaterial in which the nanoparticles are distributed. In certainpreferred embodiments the host material is a solid host material.

In certain embodiments, the optical material further includes lightscatterers distributed in the material.

In certain embodiments, an optical component further includes a supportelement. Preferably, the support element is optically transparent tolight emitted from the light source and to light emitted from thenanoparticles.

In certain embodiments, an optical component including a support elementcan serve as a cover plate for the lighting fixture.

In certain embodiments, the support element comprises a light diffusercomponent of the lighting fixture.

In certain embodiments, the support element is rigid.

In certain embodiments, the support element is flexible.

In certain embodiments, the lighting fixture includes an opticalmaterial described herein.

In certain embodiments, the lighting fixture includes an opticalcomponent taught herein.

In accordance with a further aspect of the present invention, there isprovided a cover plate adapted for attachment to a lighting fixture fora solid state semiconductor light emitting device, the cover platecomprising an optically transparent base plate having an inner surfaceand an outer surface and a predetermined shape based on the design ofthe lighting fixture, an optical material disposed on a major surface ofthe base plate, and means for attaching the cover plate to the lightingfixture, wherein the optical material comprises quantum confinedsemiconductor nanoparticles capable of converting light having a firstpredetermined wavelength into one or more different predeterminedwavelengths in order to supplement the spectrum of the light passingtherethrough.

In certain embodiments, for example, where a first predeterminedwavelength is to be converted into more one or more differentpredetermined wavelengths, the optical material comprises one or moredifferent types of quantum confined semiconductor nanoparticles (basedon composition, structure and/or size), wherein each different type ofquantum confined semiconductor nanoparticle can convert a portion of thefirst predetermined wavelength to one or more different predeterminedwavelengths. In such case, one or more different predeterminedwavelengths are selected to meet or compensate for one or more of thespectral deficiencies of the light source for which the cover plate inintended for use.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In certain embodiments, optical material includes quantum confinedsemiconductor nanoparticles that are capable of converting a firstpredetermined wavelength in the blue spectral region and into one ormore different predetermined wavelength in the red spectral region. Incertain embodiments, the optical component is capable of converting afirst predetermined wavelength in the blue spectral region into one ormore different predetermined wavelengths in the orange to red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the cyanspectral region. In certain embodiments, the optical component iscapable of converting a first predetermined wavelength in the bluespectral region into one or more different predetermined wavelengths inthe orange spectral region. In certain embodiments, the opticalcomponent is capable of converting a first predetermined wavelength inthe blue spectral region into one or more predetermined wavelengths inthe red spectral region and one or more different predeterminedwavelengths in the orange spectral region. In certain embodiments,optical material comprises quantum confined semiconductor nanoparticlescapable of emitting light in one or more other spectral regions in whichthe light source has a deficiency.

In certain embodiments, the optical material further comprises a hostmaterial in which the nanoparticles are distributed. In certainpreferred embodiments the host material is a solid host material.

In certain embodiments, the optical material further includes lightscattering particles distributed in the host material.

In certain embodiments, the optical material is at least partiallyencapsulated.

In certain embodiments, the optical material is fully encapsulated.

In certain embodiments, a cover plate comprises an optical materialdescribed herein.

In certain embodiments, a cover plate comprises an optical componenttaught herein.

In accordance with a further aspect of the present invention, there isprovided a cover plate adapted for attachment to a solid statesemiconductor light emitting device, the cover plate comprising anoptically transparent base plate having an inner surface and an outersurface and a predetermined shape based on the design of the lightingdevice, an optical material disposed on a major surface of the baseplate, and means for attaching the cover plate to the lighting device(preferably the lighting emitting face of the device), wherein theoptical material comprises quantum confined semiconductor nanoparticlescapable of converting light having a first predetermined wavelength intoone or more different predetermined wavelengths in order to supplementthe spectrum of the light passing therethrough.

In certain embodiments, for example, where a first predeterminedwavelength is to be converted into more one or more differentpredetermined wavelengths, the optical material comprises one or moredifferent types of quantum confined semiconductor nanoparticles (basedon composition, structure and/or size), wherein each different type ofquantum confined semiconductor nanoparticles can convert a portion ofthe first predetermined wavelength to one or more differentpredetermined wavelengths. In such case, one or more differentpredetermined wavelengths are selected to meet or compensate for one ormore of the spectral deficiencies of the light source for which thecover plate in intended for use.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In certain embodiments, optical material includes quantum confinedsemiconductor nanoparticles that are capable of converting a firstpredetermined wavelength in the blue spectral region and into one ormore different predetermined wavelength in the red spectral region. Incertain embodiments, the optical component is capable of converting afirst predetermined wavelength in the blue spectral region into one ormore different predetermined wavelengths in the orange to red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the cyanspectral region. In certain embodiments, the optical component iscapable of converting a first predetermined wavelength in the bluespectral region into one or more different predetermined wavelengths inthe orange spectral region. In certain embodiments, the opticalcomponent is capable of converting a first predetermined wavelength inthe blue spectral region into one or more predetermined wavelengths inthe red spectral region and one or more different predeterminedwavelengths in the orange spectral region. In certain embodiments,optical material comprises quantum confined semiconductor nanoparticlescapable of emitting light in one or more other spectral regions in whichthe light source has a deficiency.

In certain embodiments, the optical material further comprises a hostmaterial in which the nanoparticles are distributed. In certainpreferred embodiments the host material is a solid host material.

In certain embodiments, the optical material further includes lightscattering particles distributed in the host material.

In certain embodiments, the optical material is at least partiallyencapsulated.

In certain embodiments, the optical material is fully encapsulated.

In certain embodiments, a cover plate comprises an optical materialdescribed herein.

In certain embodiments, a cover plate comprises an optical componenttaught herein.

In accordance with yet a further aspect of the present invention, thereis provided a method for improving the lumens per watt efficiency of awhite light emitting solid state semiconductor light emitting devicehaving a spectral output including emissions in the blue and yellowspectral regions, the method comprising passing at least a portion ofthe blue emission into an optical material to convert at least a portionof the blue spectral emission into one or more emissions in a range fromabout 575 to about 650 nm, the optical material comprising quantumconfined semiconductor nanoparticles.

In certain embodiments, for example, the optical material can convert atleast a portion of the blue spectral emission into one or more emissionsin a range from about 580 nm to about 630 nm, from about 590 nm to about630 nm, from about 600 nm to about 620 nm, etc. In certain embodiments,the wavelength can be about 616 nm.

In certain embodiments, one or more different types of quantum confinedsemiconductor nanoparticles that emit at different predeterminedwavelengths can be included in one or more different optical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments, the method can include an optical materialdescribed herein.

In certain embodiments, the method can include an optical componenttaught herein.

In certain embodiments, including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In accordance with yet a further aspect of the present invention, thereis provided a method for improving the lumens per watt efficiency of awhite light emitting solid state semiconductor light emitting devicehaving a spectral output including emissions in the blue and yellowspectral regions, the method comprising passing at least a portion ofthe blue emission into an optical material to convert at least a portionof the blue spectral emission into one or more emissions in a range fromabout 450 nm to about 500 nm, the optical material comprising quantumconfined semiconductor nanoparticles.

In certain embodiments, the method can include an optical materialdescribed herein.

In certain embodiments, the method can include an optical componenttaught herein.

The foregoing, and other aspects and embodiments described herein allconstitute embodiments of the present invention.

As used herein, “encapsulation” refers to protection against aparticular element or compound, for example, oxygen and/or water. Incertain embodiments, encapsulation can be complete (also referred toherein as full encapsulation). In certain embodiments, encapsulation canbe less than complete (also referred to herein as partialencapsulation).

Additional information concerning quantum confined semiconductornanoparticles, light scatterers, host materials, support elements, otherfeatures and elements of the foregoing, and other information usefulwith the present inventions is provided below.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention as claimed. Other embodimentswill be apparent to those skilled in the art from consideration of thespecification and practice of the invention disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a schematic cross section of an example of an embodiment of asolid state lighting device of the invention.

FIG. 2 is a schematic cross section of an example of an arrangement of alight source and an example of an embodiment of an optical component inaccordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION

Various aspects and embodiments of the present inventions will befurther described in the following detailed description.

Quantum confined semiconductor nanoparticles can confine electrons andholes and have a photoluminescent property to absorb light and re-emitdifferent wavelength light. Color characteristics of emitted light fromquantum confined semiconductor nanoparticles depend on the size of thequantum confined semiconductor nanoparticles and the chemicalcomposition of the quantum confined semiconductor nanoparticles.

Quantum confined semiconductor nanoparticles include at least one typeof quantum confined semiconductor nanoparticle with respect to chemicalcomposition, structure, and size. The type(s) of quantum confinedsemiconductor nanoparticles included in an optical component inaccordance with the invention are determined by the wavelength of lightto be converted and the wavelengths of the desired light output. Asdiscussed herein, quantum confined semiconductor nanoparticles may ormay not include a shell and/or a ligand on a surface thereof. In certainembodiments, a shell and/or ligand can passivate quantum confinedsemiconductor nanoparticles to prevent agglomeration or aggregation toovercome the Van der Waals binding force between the nanoparticles. Incertain embodiments, the ligand can comprise a material having anaffinity for any host material in which a quantum confined semiconductornanoparticle may be included. As discussed herein, in certainembodiments, a shell comprises an inorganic shell.

In certain embodiments, one or more different types of quantum confinedsemiconductor nanoparticles (based on composition, structure and/orsize) may be included in a host material, wherein each type is selectedto obtain light having a predetermined color.

In accordance with one aspect of the present invention, there isprovided a solid state lighting device comprising a light source capableof emitting white light including a blue spectral component and having adeficiency in a spectral region, and an optical component that ispositioned to receive at least a portion of the light generated by thelight source, the optical component comprising an optical material forconverting at least a portion of the blue spectral component of thelight to one or more predetermined wavelengths such that light emittedby the solid state lighting device includes light emission from thelight source is supplemented with light emission at one or morepredetermined wavelengths, wherein the optical material comprisesquantum confined semiconductor nanoparticles.

In certain embodiments, for example, wherein the light source emitswhite light with more than one spectral deficiency, the opticalcomponent can comprise an optical material including one or moredifferent types of quantum confined semiconductor nanoparticles (basedon composition, structure and/or size), wherein each different type ofquantum confined semiconductor nanoparticle can convert a portion of theblue spectral component of the light to a predetermined wavelength thatis different from the predetermined wavelength emitted by at least oneof any other type of quantum confined semiconductor nanoparticlesincluded in the optical material.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In other embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical components in a stacked arrangement. In such embodiments, eachoptical component can include one or more optical materials as describedabove.

In embodiments including two or more different types of quantum confinedsemiconductor nanoparticles that emit at different predeterminedwavelengths, light emitted by the solid state lighting device includeslight emission that is supplemented with light emission at one or moredifferent predetermined wavelengths. In such case, the two or moredifferent predetermined wavelengths are selected to meet or compensatefor one or more of the spectral deficiencies of the light source. Forexample, typical white-emitting semiconductor LEDs emit white light withspectral deficiencies, for example, in the red, orange, and cyanspectral regions of the spectrum.

In certain embodiments, a solid state lighting device can include anoptical component for adding saturated red light to the light sourcelight output. This can provide more saturated red color for the samepower input, or equivalent red power for lower electrical powerconsumption.

In certain embodiments, a solid state lighting device can include anoptical component for adding light in the orange to red spectral region(e.g., from about 575 nm to about 650 nm) to the light source output.

In certain embodiments, a solid state lighting device can add cyan lightto the light source light output.

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alsoincrease the General Color Rendering Index (R_(a)) of light output fromthe light source. For example, in certain embodiments, the opticalcomponent can increase the General Color Rendering Index (R_(a)) oflight output from the light source by at least 10%. In certainembodiments, the General Color Rendering Index (R_(a)) is increased to apredetermined General Color Rendering Index (R_(a)).

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alter thecorrelated color temperature (CCT) of light output from the lightsource. In certain embodiments, the optical component can lower thecorrelated color temperature of light output from the light source by,for example, at least about 1000K; at least about 2000K, at least 3000K,at least 4000K, etc.

In certain embodiments, the lumens per watt efficiency of the lightsource is not substantially affected by alteration of the CCT throughuse of the optical component.

In certain embodiments, the CCT is altered to a predetermined CCT.

In certain embodiments, the CCT is altered to a predetermined CCT.

In certain preferred embodiments, quantum confined semiconductornanoparticles comprise semiconductor nanocrystals.

In certain embodiments, the quantum confined semiconductor nanoparticleshave a solid state quantum efficiency of at least 40%. In certainembodiments, the quantum confined semiconductor nanoparticles have asolid state quantum efficiency of at least 50%. In certain embodiments,the quantum confined semiconductor nanoparticles have a solid statequantum efficiency of at least 60%.

In certain embodiments, the quantum confined semiconductor nanoparticlesmaintain at least 40% efficiency during use of the optical component.

In certain preferred embodiments, the optical material comprises quantumconfined semiconductor nanoparticles capable of emitting red light. Inother certain preferred embodiments, the optical material comprisesquantum confined semiconductor nanoparticles capable of emitting lightin the orange to red spectral region.

In certain embodiments, an optical material comprises quantum confinedsemiconductor nanoparticles distributed in a host material. Preferably,the host material comprises a solid host material. Examples of a hostmaterial useful in various embodiments and aspect of the inventionsdescribed herein include polymers, monomers, resins, binders, glasses,metal oxides, and other nonpolymeric materials. Preferred host materialsinclude polymeric and non-polymeric materials that are at leastpartially transparent, and preferably fully transparent, to preselectedwavelengths of light. In certain embodiments, the preselectedwavelengths can include wavelengths of light in the visible (e.g.,400-700 nm) region of the electromagnetic spectrum. Preferred hostmaterials include cross-linked polymers and solvent-cast polymers.Examples of preferred host materials include, but are not limited to,glass or a transparent resin. In particular, a resin such as anon-curable resin, heat-curable resin, or photocurable resin is suitablyused from the viewpoint of processability. As specific examples of sucha resin, in the form of either an oligomer or a polymer, a melamineresin, a phenol resin, an alkyl resin, an epoxy resin, a polyurethaneresin, a maleic resin, a polyamide resin, polymethyl methacrylate,polyacrylate, polycarbonate, polyvinyl alcohol, polyvinylpyrrolidone,hydroxyethylcellulose, carboxymethylcellulose, copolymers containingmonomers forming these resins, and the like. Other suitable hostmaterials can be identified by persons of ordinary skill in the relevantart.

In certain embodiments and aspects of the inventions contemplated bythis disclosure, a host material comprises a photocurable resin. Aphotocurable resin may be a preferred host material in certainembodiments, e.g., embodiments in which the composition is to bepatterned. As a photocurable resin, a photo-polymerizable resin such asan acrylic acid or methacrylic acid based resin containing a reactivevinyl group, a photo-crosslinkable resin which generally contains aphoto-sensitizer, such as polyvinyl cinnamate, benzophenone, or the likemay be used. A heat-curable resin may be used when the photo-sensitizeris not used. These resins may be used individually or in combination oftwo or more.

In certain embodiments and aspects of the inventions contemplated bythis disclosure, a host material comprises a solvent-cast resin. Apolymer such as a polyurethane resin, a maleic resin, a polyamide resin,polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol,polyvinylpyrrolidone, hydroxyethylcellulose, carboxymethylcellulose,copolymers containing monomers forming these resins, and the like can bedissolved in solvents known to those skilled in the art. Uponevaporation of the solvent, the resin forms a solid host material forthe semiconductor nanoparticles.

In certain embodiments, light scatterers and/or other additives (e.g.,wetting or leveling agents) can also be included in optical material.

Examples of light scatterers (also referred to herein as scatterers orlight scattering particles) that can be used in the embodiments andaspects of the inventions described herein, include, without limitation,metal or metal oxide particles, air bubbles, and glass and polymericbeads (solid or hollow). Other light scatterers can be readilyidentified by those of ordinary skill in the art. In certainembodiments, scatterers have a spherical shape. Preferred examples ofscattering particles include, but are not limited to, TiO₂, SiO₂,BaTiO₃, BaSO₄, and ZnO. Particles of other materials that arenon-reactive with the host material and that can increase the absorptionpathlength of the excitation light in the host material can be used. Incertain embodiments, light scatterers may have a high index ofrefraction (e.g., TiO₂, BaSO₄, etc) or a low index of refraction (gasbubbles).

Selection of the size and size distribution of the scatterers is readilydeterminable by those of ordinary skill in the art. The size and sizedistribution can be based upon the refractive index mismatch of thescattering particle and the host material in which it the lightscatterer is to be dispersed, and the preselected wavelength(s) to bescattered according to Rayleigh scattering theory. The surface of thescattering particle may further be treated to improve dispersability andstability in the host material. In one embodiment, the scatteringparticle comprises TiO₂ (R902+ from DuPont) of 0.2 μm particle size, ina concentration in a range from about 0.001 to about 5% by weight. Incertain preferred embodiments, the concentration range of the scatterersis between 0.1% and 2% by weight.

In certain embodiments, an optical material including quantum confinedsemiconductor nanoparticles and a host material can be formed from anink comprising quantum confined semiconductor nanoparticles and a liquidvehicle, wherein the liquid vehicle comprises a composition includingone or more functional groups that are capable of being cross-linked.The functional units can be cross-linked, for example, by UV treatment,thermal treatment, or another cross-linking technique readilyascertainable by a person of ordinary skill in a relevant art. Incertain embodiments, the composition including one or more functionalgroups that are capable of being cross-linked can be the liquid vehicleitself. In certain embodiments, it can be a co-solvent. In certainembodiments, it can be a component of a mixture with the liquid vehicle.In certain embodiments, the ink can further include light scatterers.

In certain preferred embodiments of the inventions contemplated by thisdisclosure, quantum confined semiconductor nanoparticles (e.g.,semiconductor nanocrystals) are distributed within the host material asindividual particles.

In certain embodiments of an optical material further including a hostmaterial, quantum confined semiconductor nanoparticles included in anoptical material in an amount is from about 0.001 to about 5 weightpercent of the host material. In certain preferred embodiments, theoptical material includes from about 0.1 to about 3 weight percentquantum confined semiconductor nanoparticles based on the weight of thehost material. In certain more preferred embodiments, the compositionincludes from about 0.5 to about 3 weight percent quantum confinedsemiconductor nanoparticles based on the weight of the host material. Incertain embodiments including light scatterers, the optical materialincludes from about 0.001 to about 5 weight percent scatterers based onthe weight of the optical material.

In certain aspects and embodiments of the inventions taught herein, theoptical component can further include a support element. In certainembodiments, optical material is disposed on the support element. Incertain embodiments, optical material is disposed on a predeterminedarea of a surface of the support.

In certain embodiments, the support element is substantially opticallytransparent. In certain embodiments, the support element is at least 90%transparent. In certain embodiments, the support element is at least 95%transparent. In certain embodiments, the support element is at least 99%transparent.

In certain embodiments, the support element is optically translucent.

In certain embodiments the support element can comprise a rigidmaterial, e.g., glass, polycarbonate, acrylic, quartz, sapphire, orother known rigid materials.

In certain embodiments, the support element can comprise a flexiblematerial, e.g., a polymeric material such as plastic (e.g. but notlimited to thin acrylic, epoxy, polycarbonate, PEN, PET, PE) or asilicone.

In certain embodiments, the support element can comprise a flexiblematerial including a silica or glass coating thereon. Preferably thesilica or glass coating is sufficiently thin to retain the flexiblenature of the base flexible material.

In certain embodiments, the support element has a transmission haze (asdefined in ASTM D1003-0095) in a range from about 0.1% to about 5%.(ASTM D1003-0095 is hereby incorporated herein by reference.) In certainembodiments, one or both of the major surfaces of the support element issmooth.

In certain embodiments, one or both major surfaces of the supportelement can be corrugated.

In certain embodiments, one or both major surfaces of the supportelement can be roughened.

In certain embodiments, one or both major surfaces of the supportelement can be textured.

In certain embodiments, one or both major surfaces of the supportelement can be concave.

In certain embodiments, one or both major surfaces of the supportelement can be convex.

In certain embodiments, one major surface of the support element cancomprise microlenses.

In certain embodiments, the thickness of the carrier substrate issubstantially uniform.

In certain embodiments, the geometrical shape and dimensions of asupport element can be selected based on the particular end-useapplication.

In certain embodiments, an optical component includes at least one layerincluding one or more optical materials comprising quantum confinedsemiconductor nanoparticles.

In certain embodiments including more than one type of quantum confinedsemiconductor nanoparticles, each type can be included in a separatelayer.

In certain embodiments, the optical material is disposed across a majorsurface of the support element.

In certain embodiments, the optical material is disposed as anuninterrupted layer across a major surface of the support element.

In certain embodiments, a layer of optical material can have a thicknessfrom about 0.1 to about 200 microns. In certain embodiments, thethickness can be from about 10 to about 200 microns. In certainembodiments, the thickness can be from about 30 to about 80 microns.

In certain embodiments, other optional layers may also be included.

In certain embodiments, a layer can include two or more layers.

While further including may be undesirable for energy considerations,there may be instances in which a filter is included for other reasons.In such instances, a filter may be included. In certain embodiments, afilter may cover all or at least a predetermined portion of the supportelement. In certain embodiments, a filter can be included for blockingthe passage of one or more predetermined wavelengths of light. A filterlayer can be included over or under the optical material. In certainembodiments, an optical component can include multiple filter layers onvarious surfaces of the support element. In certain embodiments, a notchfilter layer can be included.

In certain embodiments, one or more anti-reflection coatings can beincluded in the optical component.

In certain embodiments, one or more wavelength selective reflectivecoatings can be included in the optical component. Such coatings can,for example, reflect light back toward the light source.

In certain embodiments, for example, an optical component may furtherinclude outcoupling members or structures across at least a portion of asurface thereof. In certain embodiments, outcoupling members orstructures may be uniformly distributed across a surface. In certainembodiments, outcoupling members or structures may vary in shape, size,and/or frequency in order to achieve a more uniform light distributionoutcoupled from the surface. In certain embodiments, outcoupling membersor structures may be positive, e.g., sitting or projecting above thesurface of optical component, or negative, e.g., depressions in thesurface of the optical component, or a combination of both.

In certain embodiments, an optical component can further include a lens,prismatic surface, grating, etc. on the surface thereof from which lightis emitted. Other coatings can also optionally be included on suchsurface.

In certain embodiments, outcoupling members or structures can be formedby molding, embossing, lamination, applying a curable formulation(formed, for example, by techniques including, but not limited to,spraying, lithography, printing (screen, inkjet, flexography, etc),etc.).

In certain embodiments, a support element can include light scatterers.

In certain embodiments, a support element can include air bubbles or airgaps.

In certain embodiments, an optical component can include one or moremajor, surfaces with a flat or matte finish.

In certain embodiments, an optical component can include one or moresurfaces with a gloss finish.

In certain aspects and embodiments of the inventions taught herein, anoptical component can optionally further include a cover, coating orlayer for protection from the environment (e.g., dust, moisture, and thelike) and/or scratching or abrasion.

In certain embodiments, the optical material is at least partiallyencapsulated.

In certain embodiments, the optical material is at least partiallyencapsulated by a barrier material. In certain embodiments, the opticalmaterial is at least partially encapsulated by a=material that issubstantially impervious to oxygen. In certain embodiments, the opticalmaterial is at least partially encapsulated by a material that issubstantially impervious to moisture (e.g., water). In certainembodiments, the optical material is at least partially encapsulated bya material that is substantially impervious to oxygen and moisture. Incertain embodiments, for example, the optical material can be sandwichedbetween substrates. In certain embodiments, one or both of thesubstrates can comprise glass plates. In certain embodiments, forexample, the optical material can be sandwiched between a substrate(e.g., a glass plate) and a barrier film. In certain embodiments, theoptical material can be sandwiched between two barrier films orcoatings.

In certain embodiments, the optical material is fully encapsulated. Incertain embodiments, for example, the optical material can be sandwichedbetween substrates (e.g., glass plates) that are sealed by a perimeterseal. In certain embodiments, for example, the optical material can bedisposed on a substrate (e.g., a glass support) and fully covered bybarrier film. In certain embodiments, for example, the optical materialcan be disposed on a substrate (e.g., a glass support) and fully coveredby protective coating. In certain embodiments, the optical material canbe sandwiched between two barrier films or coatings that are sealed by aperimeter seal.

Example of suitable barrier films or coatings include, withoutlimitation, a hard metal oxide coating, a thin glass layer, and Barixcoating materials available from Vitex Systems, Inc. Other barrier filmsor coating can be readily ascertained by one of ordinary skill in theart.

In certain embodiments, more than one barrier film or coating can beused to encapsulate the optical material.

Examples of light sources include, without limitation, solid state lightemitting devices (preferably, a white-light emitting LED) A light sourcepreferably emits in the visible region of the electromagnetic spectrum.

In certain embodiments, a system can include a single light source.

In certain embodiments, a system can include a plurality of lightsources.

In certain embodiments including a plurality of light sources, theindividual light sources can be the same or different.

In certain embodiments including a plurality of light sources, eachindividual light sources can emit light having a wavelength that is thesame as or different from that emitted by each of the other lightsources.

In certain embodiments including a plurality of light sources, theindividual light sources can be arranged as an array.

In certain preferred embodiments, the white light emitting LED comprisesa blue light emitting semiconductor LED including a phosphor materialfor converting the blue LED light output to white light.

In certain embodiments, for example, a blue light emitting LED componentincluded in the white light emitting LED comprises e.g., (In)GaN blue.

In certain embodiments, a blue LED can emit light in a range from about400 nm to about 500 nm.

In certain embodiments, the white light emitting LED comprises a UVlight emitting semiconductor LED including a phosphor material forconverting the UV LED light output to white light.

In certain embodiments, the weight ratio of quantum confinedsemiconductor nanoparticles to scatterers is from about 1:100 to about100:1.

As described herein, in certain embodiments of the present invention, asolid state lighting device comprises a light source capable ofgenerating light, and an optical component positioned to receive atleast a portion of the light generated by the light source and convertat least a portion of the light so received to one or more predeterminedwavelengths such that the light emitted by the solid state lightingdevice includes light emission from the light source supplemented withlight emission at one or more predetermined wavelengths, wherein theoptical component includes an optical material comprises quantumconfined semiconductor nanoparticles.

In certain embodiments, the optical material is not in direct contactwith the light source. In certain embodiments, the optical component isnot in direct contact with the light source. Preferably the temperatureat the location of the nanoparticles during operation of the solid statelighting device is less than 90° C., less than 75° C., 60° C. or less,50° C. or less, 40° C. or less. In certain preferred embodiments, thetemperature at the location of the nanoparticles during operation of thesolid state lighting device is in a range from about 30° C. to about 60°C.

In certain embodiments, the light source comprises a white LED (e.g., ablue emitting semiconductor LED that is encapsulated with an encapsulantincluding phosphor material (e.g., typically a yellow phosphor material)for converting the blue LED light output to white), and the opticalcomponent comprises an optical material comprising quantum confinedsemiconductor nanoparticles capable of emitting red light.

In certain embodiments of a solid state lighting device in accordancewith the invention that include, e.g., a light source comprising a whitelight emitting LED and an optical component comprising an opticalmaterial comprising quantum confined semiconductor nanoparticles thatcan emit light in the orange to red spectral region, an emission in theorange to red spectral region is added to the light output of the solidstate lighting device. The addition of the nanoparticles with apredetermined emission wavelength in the spectral range from about 575nm to about 650 nm can improve the lumens per watt efficiency of thesolid state lighting device without increasing the power requirementsthereof.

FIG. 1 depicts in schematic form an example of an embodiment of solidstate lighting device 10 of the present disclosure. One or more lightsources 20, depicted as a plurality of LEDs, are included in the solidstate lighting device. In certain embodiments, the light source(s)comprises a white light emitting device that emits white light includinga blue spectral component and having a deficiency in at least onespectral region. The solid state lighting device includes an opticalcomponent 50 positioned to receive at least a portion of the white lightgenerated by the light source. The optical component comprises anoptical material for converting at least a portion of the blue spectralcomponent of the white light to one or more predetermined wavelengthssuch that light emitted by the solid state lighting device includeswhite light emission from the light source supplemented with lightemission at one or more predetermined wavelengths in a deficientspectral region of the light source. The optical material comprisesquantum confined semiconductor nanoparticles, and can further includelight scattering particles. As described herein, in certain embodiments,quantum confined semiconductor nanoparticles included in an opticalmaterial comprise a semiconductor nanocrystal including a corecomprising a semiconductor material and an inorganic shell disposed onat least a portion of a surface of the core. In the depicted example,the optical component is not in direct contact with the light sources.In the depicted example, the optical component includes a supportelement that can serve as a cover plate for the solid state lightingdevice. In certain embodiments, the support element comprises a lightdiffuser component of the solid state lighting device. In the depictedexample, the optical component 50 includes a layer of optical material(as described herein) 60 disposed on a predetermined region of a firstsubstrate (e.g., an optically transparent support element) 70 andcovered by a second opposed substrate 71.

FIG. 2 depicts in schematic form an example of another embodiment of anoptical component 190 including a layered arrangement of two differentoptical materials 400, 420, each including quantum confinedsemiconductor nanocrystals different from the other. The opticalcomponent 190 is positioned to receive at least a portion of the whitelight 430 generated by the light source 410, shown as an LED. The LED410 emits white light 430 including a blue spectral component and havinga deficiency in at least one spectral region. The optical materialincluded in the optical component converts a portion of the bluespectral portion of the white light to one or more predeterminedwavelengths to supplement the light source output 430 with lightemission at one or more predetermined wavelengths 450, 460 in adeficient spectral region of the light source.

Advantageously, in certain embodiments of the present invention, anoptical material comprising red-emitting quantum confined semiconductornanoparticles can compensate for the red spectral deficiency while alsolowering the correlated color temperature of a white light emitting LED.Such optical material can alter the light output from the light sourcesuch that the General Color Rendering Index (R_(a)) of the light outputfrom the device is increased compared to that of light emitted directlyfrom the light source. Such optical material can alter the light outputfrom the light source such that the correlated color temperature of thelight output from the device has a lower correlated color temperaturethan that of the light emitted directly from the light source.

General Color Rendering Index (which can be abbreviated as R_(a).), asused herein refers to the common definition of color rendering index asa mean value for 8 standard color samples (R₁₋₈).

In certain embodiments of a solid state lighting device in accordancewith the invention that include, e.g., a light source comprising a whitelight emitting LED (including an LED emitting in the blue spectralregion with a yellow phosphor film for creating a white LED output) andan optical component comprising an optical material comprising orange(e.g., about 575 nm to about 595 nm) emitting quantum confinedsemiconductor nanoparticles, an orange emission component is added tothe light output of the solid state lighting device. The addition of thenanoparticles with a predetermined emission wavelength in the orangespectral region can improve the lumens per watt efficiency of the solidstate lighting device without increasing the power requirements thereof.

In certain embodiments of a solid state lighting device in accordancewith the invention that include, e.g., a light source comprising a whitelight emitting LED (including an LED emitting in the blue spectralregion with a yellow phosphor film for creating a white LED output) andan optical component comprising an optical material comprising cyanemitting quantum confined semiconductor nanoparticles, a cyan emissioncomponent is added to the light output of the solid state lightingdevice. The addition of the nanoparticles with a predetermined emissionwavelength in the cyan spectral region can improve the lumens per wattefficiency of the solid state lighting device without increasing thepower requirements thereof as well as the CRI.

In accordance with another aspect of the present invention, there isprovided an endoscopy light source comprising a solid state lightingdevice taught herein.

In accordance with another aspect of the present invention, there isprovided an endoscopy light source comprising an optical componenttaught herein.

In accordance with another aspect of the present invention, there isprovided an endoscopy lighting system comprising a solid state lightingdevice taught herein.

In accordance with another aspect of the present invention, there isprovided an endoscopy lighting system comprising an optical componenttaught herein.

Endoscopic lighting devices and systems can be improved by including anoptical component and/or a solid state lighting device taught herein.Performance of endoscopic systems can be enhanced by the characteristicsof light obtainable from inclusion of an optical component describedherein as a component of the endoscopic system for altering the lightoutput of the system light source. Performance of endoscopic systems canbe enhanced by the characteristics of light obtainable from inclusion ofsolid state lighting device described herein as a light source in suchsystems. Information concerning endoscopic systems can be found, forexample, in U.S. Pat. Nos. 7,496,259; 7,488,101; and 7,466,885, thedisclosures of which are hereby incorporated herein by reference intheir entireties,

In accordance with another aspect of the present invention, there isprovided an optical component useful with a light source that emitswhite light including a blue spectral component and at least onespectral deficiency in another region of the spectrum, the opticalcomponent comprising an optical material for converting at least aportion of the blue spectral component of light output from the lightsource to one or more predetermined wavelengths, wherein the opticalmaterial comprises quantum confined semiconductor nanoparticles.

In certain preferred embodiments, a predetermined wavelength is selectedto meet or compensate for a deficiency in the spectral region of thelight source, for example, by supplementing the light output of thelight source in at least one of the spectral deficiency regions.

In certain embodiments, for example, where a light source emits whitelight with a spectral deficiency in the red spectral region, thepredetermined wavelength can be in a range from about 575 nm to about650 nm, from about 580 nm to 630 nm, from about 590 nm to about 630 nm,from about 600 nm to 620 nm, etc. In certain preferred embodiments, thewavelength is about 616 nm.

In certain embodiments, for example, where a light source emits whitelight with a spectral deficiency in the cyan spectral region, theoptical material can comprise one or more different types of quantumconfined semiconductor nanoparticles that can emit at one or morepredetermined wavelengths in a range from about 450 nm to about 500 nm.

In certain embodiments, the optical component includes an opticalmaterial comprising one or more different types of quantum confinedsemiconductor nanoparticles (based on composition, structure and/orsize), wherein each different type of quantum confined semiconductornanoparticles emits light at predetermined wavelength that is differentfrom the predetermined wavelength emitted by any other type of quantumconfined semiconductor nanoparticles included in the optical material,and wherein one or more different predetermined wavelengths are selectedsuch that the optical material will compensate for one or more spectraldeficiencies of the intended light source.

In certain embodiments including one or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alsoincrease the General Color Rendering Index (R_(a)) of light output fromthe light source. For example, in certain embodiments, the opticalcomponent can increase the General Color Rendering Index (R_(a)) oflight output from the light source by at least 10%. In certainembodiments, the General Color Rendering Index (R_(a)) is increased to apredetermined General Color Rendering Index (R_(a)).

In certain embodiments, compensation of one or more spectraldeficiencies of the light source by the optical component can alter thecorrelated color temperature (CCT) of light output from the lightsource. In certain embodiments, the optical component can lower thecorrelated color temperature of light output from the light source by,for example, at least about 1000K; at least about 2000K, at least 3000K,at least 4000K, etc.

In certain embodiments, the lumens per watt efficiency of the lightsource is not substantially affected by alteration of the CCT throughuse of the optical component.

In certain embodiments, the CCT is altered to a predetermined CCT.

In certain preferred embodiments, quantum confined semiconductornanoparticles comprise semiconductor nanocrystals.

In certain embodiments, the quantum confined semiconductor nanoparticleshave a solid state quantum efficiency of at least 40%. In certainembodiments, the quantum confined semiconductor nanoparticles have asolid state quantum efficiency of at least 50%. In certain embodiments,the quantum confined semiconductor nanoparticles have a solid statequantum efficiency of at least 60%.

In certain embodiments, the quantum confined semiconductor nanoparticlesmaintain at least 40% efficiency during use of the optical component.

In certain preferred embodiments, the optical material comprises quantumconfined semiconductor nanoparticles capable of emitting red light. Inother certain preferred embodiments, the optical material comprisesquantum confined semiconductor nanoparticles capable of emitting lightin the orange to red spectral region.

In certain embodiments, the optical material further comprises a hostmaterial in which the quantum confined semiconductor nanoparticles aredistributed. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 0.001 to about 5 weight percent of the weight of thehost material. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 0.5 to about 3 weight percent of the weight of the hostmaterial. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 1 to about 3 weight percent of the weight of the hostmaterial. In certain embodiments, quantum confined semiconductornanoparticles are included in the optical material in an amount in arange from about 1 to about 2 weight percent of the weight of the hostmaterial.

In certain embodiments, the optical material further comprises lightscatterers.

In certain embodiments, the light scatterers comprise light scatteringparticles. In certain embodiments, light scattering particles areincluded in the optical material in an amount in a range from about0.001 to about 5 weight percent of the weight of the host material. Incertain embodiments, light scattering particles are included in theoptical material in an amount in a range from about 0.5 to about 3weight percent of the weight of the host material. In certainembodiments, light scattering particles are included in the opticalmaterial in an amount in a range from about 1 to about 3 weight percentof the weight of the host material. In certain embodiments, lightscattering particles are included in the optical material in an amountin a range from about 1 to about 2 weight percent of the weight of thehost material.

In certain embodiments, an optical component further includes a supportelement. Preferably, the support element is optically transparent tolight emitted from the light source and to light emitted from thenanoparticles.

In certain embodiments, an optical component including a support elementcan serve as a cover plate for the solid state lighting device.

In certain embodiments, the support element comprises a light diffusercomponent of the solid state lighting device.

In certain embodiments, the support element is rigid.

In certain embodiments, the support element is flexible.

In certain embodiments, the geometrical shape and dimensions of asupport element can be selected based on the particular end-useapplication (e.g., lamp, solid state lighting device, lighting fixture,or other apparatus or device).

In certain embodiments, the optical material comprising quantum confinedsemiconductor nanoparticles is disposed over a surface of a supportelement. Preferably, the optical material is disposed over a surface ofthe support element facing the light source.

In certain embodiments, the optical material is disposed as one or morelayers over a predetermined area of the surface of the support element.

In certain embodiments, the layer comprises an optical material thatfurther includes a host material in which the quantum confinedsemiconductor nanoparticles are distributed. In certain embodiments, thelayer includes from about 0.001 to about 5 weight percent quantumconfined semiconductor nanoparticles based on the weight of the hostmaterial. In certain embodiments, the layer further comprises lightscatterers. In certain embodiments, light scatterers are included in thelayer in an amount in the range from about 0.001 to about 5 weightpercent of the weight of the host material.

In certain embodiments, a layer including optical material including ahost material has a thickness, for example, from about 0.1 micron toabout 1 cm. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 0.1 to about 200microns. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 10 to about 200microns. In certain embodiments, a layer including optical materialincluding a host material has a thickness from about 30 to about 80microns.

In certain embodiments, the optical component can convert at least 10%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert at least 30%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert at least 60%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert at least 90%of the emission in the blue spectral region to one or more predeterminedwavelengths.

In certain embodiments, the optical component can convert from about 50%to about 75% of the emission in the blue spectral region to one or morepredetermined wavelengths.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material are cadmium free.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material comprise a III-V semiconductor material.

In certain embodiments, quantum confined semiconductor nanoparticlesincluded in an optical material comprise a semiconductor nanocrystalincluding a core comprising a semiconductor material and an inorganicshell disposed on at least a portion of a surface of the core.

In certain embodiments, the optical material is at least partiallyencapsulated.

In certain embodiments, the optical material is fully encapsulated.

In accordance with another aspect of the present invention, there isprovided a lighting fixture adapted to receive a light source, whereinthe fixture includes an optical component that is positioned in thefixture relative to the position of the light source such that at leasta portion of the light generated by the light source passes into theoptical component before being emitted from the fixture, wherein theoptical component comprises an optical material capable of convertinglight having a first predetermined wavelength into light with having oneor more different predetermined wavelengths in order to supplement thespectrum of the light emitted from the light source, wherein the opticalcomponent comprises an optical material comprising quantum confinedsemiconductor nanoparticles.

In certain embodiments, optical component is capable of converting afirst predetermined wavelength in the blue spectral region into one ormore different predetermined wavelengths in the red spectral region.

In certain embodiments, the optical component is capable of converting afirst predetermined wavelength in the blue spectral region into one ormore different predetermined wavelengths in the orange to red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one more different predetermined wavelengths in the cyan spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the red spectralregion and one or more different predetermined wavelengths in the orangespectral region.

In certain embodiments, the optical material further comprises a hostmaterial in which the nanoparticles are distributed. In certainpreferred embodiments the host material is a solid host material.

In certain embodiments, the optical material further includes lightscattering particles distributed in the host material.

In certain embodiments, the fixture can include the optical componentand optical material taught herein.

In accordance with a further aspect of the present invention, there isprovided a cover plate adapted for attachment to a solid statesemiconductor light emitting device or a lighting fixture for a solidstate semiconductor light emitting device, the cover plate comprising anoptically transparent base plate having an inner surface and an outersurface and a predetermined shape based on the design of the device orlighting fixture, an optical material disposed on the surface(preferably the surface to face the light source) of the base plate, andmeans for attaching the cover plate to the device or lighting fixture,wherein the optical material comprises quantum confined semiconductornanoparticles capable of converting light having a first predeterminedwavelength into one or more different predetermined wavelengths in orderto supplement the spectrum of the light passing therethrough.

In certain embodiments, for example, where a first predeterminedwavelength is to be converted into more one or more differentpredetermined wavelengths, the optical material comprises one or moredifferent types of quantum confined semiconductor nanoparticles (basedon composition, structure and/or size), wherein each different type ofquantum confined semiconductor nanoparticle can convert a portion of thefirst predetermined wavelength to one or more different predeterminedwavelengths. In such case, one or more different predeterminedwavelengths are selected to meet or compensate for one or more of thespectral deficiencies of the light source for which the cover plate inintended for use.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain embodiments including two or more different opticalmaterials, such different optical materials can, for example, beincluded as separate layers of a layered arrangement and/or as separatefeatures of a patterned layer.

In certain embodiments, optical material includes quantum confinedsemiconductor nanoparticles that are capable of converting a firstpredetermined wavelength in the blue spectral region and into one ormore different predetermined wavelength in the red spectral region. Incertain embodiments, the optical component is capable of converting afirst predetermined wavelength in the blue spectral region into one ormore different predetermined wavelengths in the orange to red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the red spectralregion. In certain embodiments, the optical component is capable ofconverting a first predetermined wavelength in the blue spectral regioninto one or more different predetermined wavelengths in the cyanspectral region. In certain embodiments, the optical component iscapable of converting a first predetermined wavelength in the bluespectral region into one or more different predetermined wavelengths inthe red spectral region and one or more different predeterminedwavelengths in the orange spectral region.

In certain embodiments, the optical material further comprises a hostmaterial in which the nanoparticles are distributed. In certainpreferred embodiments the host material is a solid host material.

In certain embodiments, the optical material further includes lightscattering particles distributed in the host material.

In certain embodiments, a cover plate comprises an optical componenttaught herein.

In certain embodiments, the cover plate can include an optical materialtaught herein.

In certain embodiments the cover plate can be flexible or rigid. Incertain embodiments, the base plate can comprise materials useful forthe above-described support element. In certain embodiments, a baseplate can comprise one or more features and additional layers describedabove for the support element.

In certain embodiments and aspects of the inventions described herein,the geometrical shape and dimensions of a support element, an opticalcomponent, a base plate, and/or cover plate can be selected based on theparticular end-use application.

In certain embodiments, the optical material is at least partiallyencapsulated.

In certain embodiments, the optical material is fully encapsulated.

In accordance with yet a further aspect of the present invention, thereis provided a method for improving the lumens per watt efficiency of awhite light emitting solid state semiconductor light emitting devicehaving a spectral output including emissions in the blue and yellowspectral regions, the method comprising passing at least a portion ofthe blue emission into an optical material to convert at least a portionof the blue spectral emission to emission in a range from about 575 nmto about 650 nm, the optical material comprising quantum confinedsemiconductor nanoparticles.

In certain embodiments, for example, the optical material can convert atleast a portion of the blue spectral emission to emission in a rangefrom about 580 nm to about 630 nm, from about 590 nm to about 630 nm,from about 600 nm to about 620 nm, etc. In certain embodiments, thewavelength can be about 616 nm.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in one or more differentoptical materials.

In certain embodiments including two or more different types of quantumconfined semiconductor nanoparticles that emit at differentpredetermined wavelengths, the different types of quantum confinedsemiconductor nanoparticles can be included in two or more differentoptical materials.

In certain aspects and embodiments of the inventions taught herein, theoptical material (e.g., comprising quantum confined semiconductornanoparticles dispersed in a host material (preferably a polymer orglass)) is exposed to light flux for a period of time sufficient toincrease the photoluminescent efficiency of the optical material. Incertain embodiments, the optical material is exposed to light and heatfor a period of time sufficient to increase the photoluminescentefficiency of the optical material. In certain embodiments, the exposureto light or light and heat is continued for a period of time until thephotoluminescent efficiency reaches a substantially constant value. Incertain embodiments, an LED light source with peak wavelength of about450 nm is used as the source of light flux. Other known light sourcescan be readily identified by the skilled artisan. In certainembodiments, the light flux is from about 10 to about 100 mW/cm²,preferably from about 20 to about 35 mW/cm², and more preferably fromabout 20 to about 30 mW/cm². In embodiments that include exposing theoptical material to light and heat, the optical material is exposed tolight while at a temperature in a range from about 25° to about 80° C.In certain embodiments, the optical material (e.g., comprising quantumconfined semiconductor nanoparticles dispersed in a host material(preferably a polymer or glass)) can be encapsulated (for example, alayer of optical material can be disposed between glass plates, barrierfilms, or combinations thereof) when exposed to light, whether or notheat is also applied. In certain examples, the glass plates, barrierfilms, or combination thereof can further be sealed together around theperimeter or edge. In certain embodiments, the seal comprises barriermaterial. In certain embodiments, the seal comprises an oxygen barrier.In certain embodiments, the seal comprises a water barrier. In certainembodiments, the seal comprises an oxygen and water barrier. In certainembodiments, the seal is substantially impervious to water and/oroxygen. Examples of sealing techniques include, but are not limited to,glass-to-glass seal, glass-to-metal seal, sealing materials that aresubstantially impervious to oxygen and/or water, epoxies and othersealing materials that slow down penetration of oxygen and/or moisture.In certain embodiments, the optical material (e.g., comprising quantumconfined semiconductor nanoparticles dispersed in a host material(preferably a polymer or glass)) can be partially encapsulated whenexposed to light, whether or not heat is also applied.

Photoluminescent efficiency can be measured, for example, with use of aspectrophotometer in an integrating sphere including a NIST traceablecalibrated light source. In such embodiments, the optical material canfurther include light scattering particles and other optional additivesdescribed herein.

The present invention will be further clarified by the followingexamples, which are intended to be exemplary of the present invention.

EXAMPLES Example 1 Preparation of Semiconductor Nanocrystals Capable ofEmitting Red Light with 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acidSynthesis of CdSe Cores

1 mmol cadmium acetate is dissolved in 8.96 mmol of tri-n-octylphosphineat 100° C. in a 20 mL vial and is then dried and degassed for one hour.15.5 mmol of trioctylphosphine oxide and 2 mmol of octadecylphosphonicacid are added to a 3-neck flask and dried and degassed at 140° C. forone hour. After degassing, the Cd solution is added to the oxide/acidflask and the mixture is heated to 270° C. under nitrogen. Once thetemperature reaches 270° C., 8 mmol of tri-n-butylphosphine is injectedinto the flask. The temperature is brought back to 270° C. where 1.1 mLof 1.5 M TBP-Se is then rapidly injected. The reaction mixture is heatedat 270° C. for 15-30 minutes while aliquots of the solution are removedperiodically in order to monitor the growth of the nanocrystals. Oncethe first absorption peak of the nanocrystals reaches 565-575 nm, thereaction is stopped by cooling the mixture to room temperature. The CdSecores are precipitated out of the growth solution inside a nitrogenatmosphere glovebox by adding a 3:1 mixture of methanol and isopropanol.The cores are isolated and then dissolved in hexane for use in makingcore-shell materials.

Preparation of 3,5-Di-tert-butyl-4-hydroxybenzylphosphonic acid

3,5-Di-tert-butyl-4-hydroxybenzylphosphonic acid is obtained from PCISynthesis, 9 Opportunity Way, Newburyport, Mass. 01950.

The preparation of 3,5-Di-tert-butyl-4-hydroxybenzylphosphonic acidgenerally utilizes the following synthetic approach:

3,5-Di-tert-butyl-4-hydroxybenzylphosphonic acid can be characterized bythe following:

Melting point: 199-200° C. [Lit: 200° C.; Literature ref: J. D. Spivack,FR1555941 (1969)]

IR: 3614 cm⁻¹, 3593 cm⁻¹ (weak, O—H stretching).

¹H-NMR (CD₃OD): δ 7.10 (d, aromatic, 2H, J_(P-H)=2.6 Hz), 5.01 (s,exchanged HOD), 2.99 (d, —CH₂, 2H, J_(p-H)=21.2 Hz), 1.41 (s, —CH₃,18H).

¹³C-NMR (CD₃OD): δ 152.9 (aromatic), 137.9 (aromatic), 126.2 (aromatic),123.5 (aromatic), 34.41 (d, —CH₂, 35.75, 33.07, J_(P-C)=537.2 Hz), 34.35(—C(CH₃)₃), 29.7 (—C(CH₃)₃).

³¹P-NMR (CD₃OD): δ 26.8

The above-identified synthetic precursors included in the preparation of3,5-Di-tert-butyl-4-hydroxybenzylphosphonic acid can be characterized bythe following:

Diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate

Melting point: 119-120° C. (Lit: 118-119° C.; Literature ref: R. K.Ismagilov, Zhur. Obshchei Khimii, 1991, 61, 387).

IR: 3451 cm⁻¹ (weak, —OH, stretching), 2953 (weak, —CH₃, C—Hstretching).

¹H-NMR (CDCl₃): δ 7.066 (d, Ar—H, 2H, J_(P-H)=2.8 Hz), 5.145 (s, 1H,—OH), 4.06-3.92 (m, —CH₂CH₃, 4H, H—H and long-range P—H couplings),3.057 (d, Ar—CH ₂, 2H, J_(P-H)=21.0 Hz), 1.412 (s, —C(CH ₃)₃, 18H),1.222 (t, —CH₂CH ₃, 6H).

¹³C-NMR (CDCl₃): δ 153.98 (aromatic), 136.22 (aromatic), 126.61(aromatic), 122.07 (aromatic), 62.14 (—OCH₂CH₃, J_(P-C)=24.4 Hz), 33.63(Ar—CH₂, J_(P-C)=552.4 Hz), 34.53 [—C(CH₃)₃], 30.54 [—C(CH₃)₃], 16.66(—CH₂ CH₃, J_(P-C)=24.4 Hz).

³¹P-NMR (CDCl₃): δ 28.43.

3,5-di-tert-butyl-4-hydroxybenzyl bromide

Melting point: 51-54° C. (Lit: 52-54° C.; Literature ref: J. D. McClure,J. Org. Chem., 1962, 27, 2365)

IR: 3616 cm⁻¹ (medium, O—H stretching), 2954 cm⁻¹ (weak, alkyl C—Hstretching).

¹H-NMR (CDCl₃): δ 7.20 (s, Ar—H, 2H), 5.31 (s, —OH), 4.51 (s, —CH₂, 2H),1.44 {s, [—C(CH ₃)₃], 18H}.

¹³C-NMR (CDCl₃): δ 154.3 (aromatic), 136.5 (aromatic), 128.7 (aromatic),126.3 (aromatic), 35.8 [(—C(CH₃)₃], 34.6 (—CH₂), 30.5 [—C(CH₃)₃].

Other synthetic approaches that are known or readily ascertainable byone of ordinary skill in the relevant art can be used to prepare3,5-Di-tert-butyl-4-hydroxybenzylphosphonic acid.

Synthesis of CdSe/CdZnS Core-Shell Nanocrystals

25.86 mmol of trioctylphosphine oxide and 2.4 mmol of3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid are loaded into afour-neck flask. The mixture is then dried and degassed in the reactionvessel by heating to 120° C. for about an hour. The flask is then cooledto 75° C. and the hexane solution containing isolated CdSe cores (0.1mmol Cd content) is added to the reaction mixture. The hexane is removedunder reduced pressure. Dimethyl cadmium, diethyl zinc, andhexamethyldisilathiane are used as the Cd, Zn, and S precursors,respectively. The Cd and Zn are mixed in equimolar ratios while the S isin two-fold excess relative to the Cd and Zn. The Cd/Zn and S samplesare each dissolved in 4 mL of trioctylphosphine inside a nitrogenatmosphere glove box. Once the precursor solutions are prepared, thereaction flask is heated to 155° C. under nitrogen. The precursorsolutions are added dropwise over the course of 2 hours at 155° C. usinga syringe pump. After the shell growth, the nanocrystals are transferredto a nitrogen atmosphere glovebox to be precipitated out of the growthsolution by adding a 3:1 mixture of methanol and isopropanol. Thecore-shell nanocrystals are then isolated and dispersed in fluorobenzeneand used to make an optical material.

(3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid ligand group may alsobe referred to herein as BHT.)

Example 2 Preparation of Optical Component Including SemiconductorNanocrystals

The film listed in the Table below is prepared using optical materialincluding semiconductor nanocrystals (prepared substantially inaccordance with the synthesis described in Example 1).

The red-emitting semiconductor nanocrystals dispersed in solvent have apeak emission at 609 nm, a FWHM of 31, a solution quantum yield of 77%and a concentration of 21 mg/ml.

0.5 ml of RD-12, a low viscosity reactive diluent commercially availablefrom Radcure Corp, 9 Audrey Pl, Fairfield, N.J. 07004-3401, UnitedStates, is added to a 20 ml septum capped vial including a magneticstirrer bar, the system is closed and purged through a syringe needleunder vacuum then backfilled with nitrogen. 2.6 ml of the 21 mg/mlsuspension of the red-emitting nanocrystals is added to the vial by a 3ml syringe. Solvent is removed from the vial by vacuum stripping. 2 mlof DR-150 is then added to the vial through a syringe and the mixture ismixed using a Vortex mixer. (DR-150 is a UV-curable acrylic formulationcommercially available from Radcure.). The vessel is then backfilledwith nitrogen and the mixture is mixed using a Vortex mixer.

0.028 gram TiO₂ is next added to the open vial and the mixture is mixedwith a Vortex mixer followed by mixing with an homogenizer.

The vial is then capped and deaerated under vacuum and backfilled withnitrogen.

After mixing, the closed vial is put in an ultrasonic bath for 50minutes. Care is taken to avoid temperatures over 40° C. while thesample is in the ultrasonic bath.

The sample is stored in the dark until used to make a coating.

Tego 2500 is added before forming films on polycarbonate.

Sample material from the vial is Mayer rod coated onto a corona treatedprecleaned 1 mm thick sheet of transparent polycarbonate and cured in a5000-EC UV Light Curing Flood Lamp from DYMAX Corporation system with anH-bulb (225 mW/cm²) for 20 seconds. The thickness of the nanocrystalcontaining layer on the polycarbonate is approximately 30 microns.

The resulting film is cut to size to serve as cover plates on whitelight emitting Array PAR 30 LED lamps available from NEXXUS Lighting.

Data for Array PAR 30 LED lamps (available from NEXXUS Lighting) withand without an optical component comprising the above-prepared coverplates is provided in the following Table 1:

TABLE 1 CORRELATED COLOR GENERAL LUMENS TEMPERATURE CRI (R_(a)) ArrayPAR 30 LED 342 5079 76.4 Lamp (5000K) without nanocrystal containingcover plate Array PAR 30 LED 220 2712 89.6 Lamp (5000K) with nanocrystalcontaining cover plate (as described in above example) Array PAR 30 LED366 6412 75.7 Lamp (6500K) without nanocrystal containing cover plateArray PAR 30 LED 224 3031 91.3 Lamp (6500K) with nanocrystal containingcover plate (as described in above example)

Example 3 Preparation of Semiconductor Nanocrystals Capable of Emitting611 Nm Light with 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acidSynthesis of CdSe Cores

29.9 mmol cadmium acetate is dissolved in 436.7 mmol oftri-n-octylphosphine at 100° C. in a 250 mL 3-neck round-bottom flaskand then dried and degassed for one hour. 465.5 mmol oftrioctylphosphine oxide and 61.0 mmol of octadecylphosphonic acid areadded to a 0.5 L glass reactor and dried and degassed at 140° C. for onehour. After degassing, the Cd solution is added to the reactorcontaining the oxide/acid and the mixture is heated to 270° C. undernitrogen. Once the temperature reaches 270° C., 243.2 mmol oftri-n-butylphosphine is injected into the flask. The temperature isbrought back to 270° C. where 34 mL of 1.5 M TBP-Se is then rapidlyinjected. The reaction mixture is heated at 250° C. for 9 minutes atwhich point the heating mantle is removed from the reaction flask andthe solution is allowed to cool to ambient temperature. Once the firstabsorption peak of the nanocrystals reaches about 558 nm, the reactionis stopped by cooling the mixture to room temperature. The CdSe coresare precipitated out of the growth solution inside a nitrogen atmosphereglovebox by adding a 3:1 mixture of methanol and isopropanol. Theisolated cores are then dissolved in hexane and used to make core-shellmaterials.

Synthesis of CdSe/CdZnS Core-Shell Nanocrystals

Two identical reactions are set up whereby 25.86 mmol oftrioctylphosphine oxide and 2.4 mmol of3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid are loaded into 50 mLfour-neck round bottom flasks. The mixtures are then dried and degassedin the reaction vessels by heating to 120° C. for about an hour. Theflasks are then cooled to 70° C. and the hexane solution containingisolated CdSe cores (0.096 mmol Cd content) are added to each reactionmixture. The hexane is removed under reduced pressure. Dimethyl cadmium,diethyl zinc, and hexamethyldisilathiane are used as the Cd, Zn, and Sprecursors, respectively. The Cd and Zn are mixed in equimolar ratioswhile the S is in two-fold excess relative to the Cd and Zn. Two sets ofCd/Zn (0.29 mmol of dimethylcadmium and diethylzinc) and S (1.15 mmol ofhexamethyldisilathiane) samples are each dissolved in 4 mL oftrioctylphosphine inside a nitrogen atmosphere glove box. Once theprecursor solutions are prepared, the reaction flasks are heated to 155°C. under nitrogen. The Cd/Zn and S precursor solutions are addeddropwise to the respective reaction flasks over the course of 2 hours at155° C. using a syringe pump. After the shell growth, the nanocrystalsare transferred to a nitrogen atmosphere glovebox and precipitated outof the growth solution by adding a 3:1 mixture of methanol andisopropanol. The isolated core-shell nanocrystals are then dispersed intoluene.

Example 4 Preparation of Optical Component Including SemiconductorNanocrystals

The following film is prepared using optical material includingsemiconductor nanocrystals (prepared substantially in accordance withthe synthesis described in Example 3).

The semiconductor nanocrystals comprise red-emitting semiconductornanocrystals dispersed in toluene and have a peak emission at 611 nm, aFWHM of about 32 nm, a solution quantum yield of 70% and a concentrationof 20.4 mg/ml.

5.5 ml of the 20.4 mg/ml suspension of the red-emitting nanocrystals isadded from a 6 mL syringe to a 20 ml septum capped vial including amagnetic stirrer bar, the system is closed and purged through a syringeneedle under vacuum then backfilled with nitrogen. Approximately half ofthe solvent is removed from the vial by vacuum stripping. 1.0 ml ofRD-12, a low viscosity reactive diluent commercially available fromRadcure Corp, 9 Audrey Pl, Fairfield, N.J. 07004-3401 is added. 4.0 mlof DR-150 is then added to the vial through a syringe and the mixture ismixed using a Vortex mixer. (DR-150 is a UV-curable acrylic formulationcommercially available from Radcure.)

0.3 ml of a 10% solution of Tego 2500 in toluene is added to the mixtureby syringe while mixing. Remaining solvent is removed from the vial byvacuum stripping.

The vessel is then backfilled with nitrogen and the mixture is mixedusing a Vortex mixer.

0.056 gram TiO₂ (Ti-Pure 902+ available from DuPont) is next added tothe open vial and the mixture is mixed with a Vortex mixer followed bymixing with an homogenizer.

The vial is then capped and deaerated under vacuum and backfilled withnitrogen.

After mixing, the closed vial is put in an ultrasonic bath for 50minutes. Care is taken to avoid temperatures over 40° C. while thesample is in the ultrasonic bath.

The sample is stored in the dark until used to make a coating.

Sample material from the vial is screen-printed onto a corona treatedprecleaned (using an isopropanol wipe) 1.4 mm thick polycarbonate (1%transmission haze) hexagonal cover plate and cured in a 5000-EC UV LightCuring Flood Lamp from DYMAX Corporation system with an H-bulb (225mW/cm²) for 20 seconds. The thickness of the nanocrystal containinglayer on the polycarbonate is approximately 32 microns.

The resulting cover plate is included as the face plate of a white lightemitting Array PAR 30 LED lamp available from NEXXUS Lighting.

Example 5 Preparation of Semiconductor Nanocrystals A. Preparation ofSemiconductor Nanocrystals Capable of Emitting 588 nm Light with3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid

Synthesis of CdSe Cores: 1.75 mmol cadmium acetate is dissolved in 15.7mmol of tri-n-octylphosphine at 140° C. in a 20 mL vial and then driedand degassed for one hour. 31.0 mmol of trioctylphosphine oxide and 4mmol of octadecylphosphonic acid are added to a 3-neck flask and driedand degassed at 110° C. for one hour. After degassing, the Cd solutionis added to the oxide/acid flask and the mixture is heated to 270° C.under nitrogen. Once the temperature reaches 270° C., 16 mmol oftri-n-butylphosphine is injected into the flask. The temperature isbrought back to 270° C. where 2.3 mL of 1.5 M TBP-Se is then rapidlyinjected. The reaction mixture is heated at 270° C. for 30 seconds andthen the heating mantle is removed from the reaction flask allowing thesolution to cool to room temperature. The CdSe cores are precipitatedout of the growth solution inside a nitrogen atmosphere glovebox byadding a 3:1 mixture of methanol and isopropanol. The isolated cores arethen dissolved in hexane and used to make core-shell materials.(Abs/Emission/FWHM (nm)=518/529/26.5).

Synthesis of CdSe/CdZnS Core-Shell Nanocrystals: Two identical reactionsare set up whereby 25.86 mmol of trioctylphosphine oxide and 2.4 mmol of3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid are loaded into 50 mLfour-neck round bottom flasks. The mixtures are then dried and degassedin the reaction vessels by heating to 120° C. for about an hour. Theflasks are then cooled to 70° C. and the hexane solution containingisolated CdSe cores from above (0.062 mmol Cd content) are added to therespective reaction mixture. The hexane is removed under reducedpressure. Dimethyl cadmium, diethyl zinc, and hexamethyldisilathiane areused as the Cd, Zn, and S precursors, respectively. The Cd and Zn aremixed in equimolar ratios while the S was in two-fold excess relative tothe Cd and Zn. Two sets of Cd/Zn (0.31 mmol of dimethylcadmium anddiethylzinc) and S (1.24 mmol of hexamethyldisilathiane) samples areeach dissolved in 4 mL of trioctylphosphine inside a nitrogen atmosphereglove box. Once the precursor solutions are prepared, the reactionflasks are heated to 155° C. under nitrogen. The Cd/Zn and S precursorsolutions are added dropwise to the respective reaction flasks over thecourse of 2 hours at 155° C. using a syringe pump. After the shellgrowth, the nanocrystals are transferred to a nitrogen atmosphereglovebox and precipitated out of the growth solution by adding a 3:1mixture of methanol and isopropanol. The isolated core-shellnanocrystals are then dispersed in toluene and the solutions from thetwo batches are combined

B. Preparation of Semiconductor Nanocrystals Capable of Emitting 632 nmLight with 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid

Synthesis of CdSe Cores: 29.9 mmol cadmium acetate is dissolved in 436.7mmol of tri-n-octylphosphine at 140° C. in a 250 mL 3-neck round-bottomSchlenk flask and then dried and degassed for one hour. 465.5 mmol oftrioctylphosphine oxide and 61.0 mmol of octadecylphosphonic acid areadded to a 0.5 L glass reactor and dried and degassed at 120° C. for onehour. After degassing, the Cd solution is added to the reactorcontaining the oxide/acid and the mixture is heated to 270° C. undernitrogen. Once the temperature reaches 270° C., 243.2 mmol oftri-n-butylphosphine is injected into the flask. The temperature isbrought back to 270° C. where 33.3 mL of 1.5 M TBP-Se is then rapidlyinjected. The reaction mixture is heated at 270° C. for ˜9 minutes atwhich point the heating mantle is removed from the reaction flask andthe mixture is allowed to cool to room temperature. The CdSe cores areprecipitated out of the growth solution inside a nitrogen atmosphereglovebox by adding a 3:1 mixture of methanol and isopropanol. Theisolated cores are then dissolved in hexane and used to make core-shellmaterials. (Abs/Emission/FWHM (nm)=571/592/45)

Synthesis of CdSe/CdZnS Core-Shell Nanocrystals: Three identicalreactions are conducted whereby 517.3 mmol of trioctylphosphine oxideand 48.3 mmol of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid areloaded into a 0.5 L glass reactor. The mixtures are then dried anddegassed in the reactor by heating to 120° C. for about an hour. Thereactors are then cooled to 70° C. and hexane solutions containing theisolated CdSe cores from above (1.95 mmol Cd content) are added to therespective reaction mixtures. The hexane is removed under reducedpressure. Dimethyl cadmium, diethyl zinc, and hexamethyldisilathiane areused as the Cd, Zn, and S precursors, respectively. The Cd and Zn aremixed in equimolar ratios while the S was in two-fold excess relative tothe Cd and Zn. Two sets of Cd/Zn (5.5 mmol of dimethylcadmium anddiethylzinc) and S (22 mmol of hexamethyldisilathiane) samples are eachdissolved in 80 mL of trioctylphosphine inside a nitrogen atmosphereglove box. Once the precursor solutions are prepared, the reactionflasks are heated to 155° C. under nitrogen. The precursor solutions areadded dropwise the respective reactor solutions over the course of 2hours at 155° C. using a syringe pump. After the shell growth, thenanocrystals are transferred to a nitrogen atmosphere glovebox andprecipitated out of the growth solution by adding a 3:1 mixture ofmethanol and isopropanol. The resulting precipitates are then dispersedin hexane and precipitated out of solution for a second time by adding a3:1 mixture of methanol and isopropanol. The isolated core-shellnanocrystals are then dissolved in chloroform and the solutions from thethree batches are mixed. (Abs/Emission/FWHM (nm)=610/632/40)

Example 6 Preparation of Optical Component Including Two Different Typesof Semiconductor Nanocrystals

The following film is prepared using optical material includingsemiconductor nanocrystals (prepared substantially in accordance withthe synthesis described in Example 5).

A. Optical Material Including Semiconductor Nanocrystals with a PeakEmission in the Orange Spectral Region:

The semiconductor nanocrystals prepared substantially in accordance withthe synthesis described in Example 5A comprise orange-emittingsemiconductor nanocrystals dispersed in Fluorobenzene have a peakemission at 588 nm, a FWHM of about 28 nm, a solution quantum yield of83% and a concentration of 20 mg/ml.

2.7 ml of the 20 mg/ml suspension of the red-emitting nanocrystals isadded from a 3 mL syringe to a 20 ml septum capped vial including amagnetic stirrer bar, the system is closed and purged through a syringeneedle under vacuum then backfilled with nitrogen. Approximately 90percent of the solvent is removed from the vial by vacuum stripping. 0.5ml of RD-12, a low viscosity reactive diluent commercially availablefrom Radcure Corp, 9 Audrey Pl, Fairfield, N.J. 07004-3401 is added.Remaining solvent is removed from the vial by vacuum stripping. 2.0 mlof DR-150 is then added to the vial through a syringe and the mixture ismixed using a Vortex mixer. (DR-150 is a UV-curable acrylic formulationcommercially available from Radcure.). The mixture is then placed in anultrasonic bath for approximately 15 minutes.

0.028 gram TiO₂ (Ti-Pure 902+ available from DuPont) is next added tothe open vial and the mixture is mixed with a Vortex mixer followed bymixing with an homogenizer.

The vial is then capped and deaerated under vacuum and backfilled withnitrogen.

After mixing, the closed vial is put in an ultrasonic bath for 50minutes. Care is taken to avoid temperatures over 40° C. while thesample is in the ultrasonic bath.

The sample is stored in the dark until used to make a combinedformulation with long wavelength semiconductor and additional matrixmaterial.

B. Optical Material Including Semiconductor Nanocrystals with a PeakEmission in the Red Spectral Region:

The semiconductor nanocrystals prepared substantially in accordance withthe synthesis described in Example 5B comprise orange-emittingsemiconductor nanocrystals dispersed in Chloroform and have a peakemission at 632 nm, a FWHM of about 40 nm, a solution quantum yield of70% and a concentration of 56.7 mg/ml.

99 ml of the 56.7 mg/ml suspension of the red-emitting nanocrystals isadded to a septum capped Erlenmeyer flask including a magnetic stirrerbar, the system is closed and purged through a syringe needle undervacuum then backfilled with nitrogen. Approximately 95 percent of thesolvent is removed from the vial by vacuum stripping. 46.6 ml of RD12, alow viscosity reactive diluent commercially available from Radcure Corp,9 Audrey Pl, Fairfield, N.J. 07004-3401 is added. Remaining solvent isremoved from the vial by vacuum stripping. 187 ml of DR-150 is thenadded to the vial through a syringe and the mixture is mixed using aVortex mixer. (DR-150 is a UV-curable acrylic formulation commerciallyavailable from Radcure.). The mixture is then placed in an ultrasonicbath for approximately 50 minutes.

Approximately 2.6 gram TiO₂ (Ti-Pure 902+ available from DuPont) is nextadded to the open vial as well as 12.9 grams of Esacure TPO previouslyground to reduce particle size in a ball mill machine and the mixture ismixed with a Vortex mixer followed by mixing with an homogenizer.

The vial is then capped and deaerated under vacuum and backfilled withnitrogen.

After mixing, the closed vial is put in an ultrasonic bath for 60minutes. Care is taken to avoid temperatures over 40° C. while thesample is in the ultrasonic bath. The sample is stored in the dark untilused to make a combined formulation with long wavelength semiconductorand additional matrix material.

C. Preparation of Host Material Including Spacer Beads:

0.9 ml of RD-12, a low viscosity reactive diluent commercially availablefrom Radcure Corp, 9 Audrey Pl, Fairfield, N.J. 07004-3401 and 3.8 ml ofDR-150, also available from Radcure Corp, is added to a 20 ml vial andthe mixture is mixed using a Vortex mixer. The mixture is then placed inan ultrasonic bath for approximately 30 minutes.

Approximately 0.05 gram TiO₂ (Ti-Pure 902+ available from DuPont) isnext added to the open vial as well as 0.05 grams of GL0179B6/45 spacebeads available from MO-SCI Specialty Products, Rolla, Mo. 65401 USA,and then mixed using a Vortex mixer.

After mixing, the closed vial is put in an ultrasonic bath forapproximately 50 minutes. Care is taken to avoid temperatures over 40°C. while the sample is in the ultrasonic bath. The sample is stored inthe dark until used to make a combined formulation with long wavelengthsemiconductor and additional matrix material.

D. Preparation of Optical Material & Layer Including Red and OrangeEmitting Semiconductor Nanocrystals:

An optical material is formed by adding together in a 20 ml vial, 2.52grams of the host material including spacer beads (preparedsubstantially in accordance with the procedure described in Example 6C),0.99 grams of the optical material of Example 6B and 1.01 grams of theoptical material of Example 6A. The mixture was stirred using a Vortexmixer followed by sonification in an ultrasonic bath for approximately50 minutes.

Sample material from the combination vial is dispensed onto a Hexagonshaped flat Borosilicate glass which was previously cleaned using acaustic base bath, acid rinse, deionized water rinse, and a methanolwipe. A second Hexagon plate of the same size also previously cleaned isplaced on top of the dispensed sample material and the sandwichedstructure is massaged to spread the formulation evenly between the twoglass plates. Excess formulation which squeezed out of the structure iswiped off of the outer portion of the glass and the Hexagon sandwich iscured in a 5000-EC UV Light Curing Flood Lamp from DYMAX Corporationsystem with an H-bulb (225 mW/cm²) for 10 seconds. The thickness of thenanocrystal containing layer is comprises approximately 70-79 μm(approximately 360 mg of formulation).

The Hexagon sandwich consisting of two Hexagon shaped flat plates ofBorosilicate glass with cured layer of acrylic containing a sample ofthe optical material prepared substantially as described in Example 6.

Six samples (Samples A-F) were prepared substantially as described inExample 6. Initial CCT, CRI, and External Quantum Efficiencymeasurements were taken for each sample prior to heating each sample toapproximately 50° C. and irradiating the sample with approximately 30mW/cm2 of 450 nm blue light for the time specified in following Table 2for each of the samples. CCT, CRI, and EQE measurements were taken afterthe irradiation time listed for the respective sample. The data is setforth in the following Table 2.

TABLE 2 Irradiation at 50° C. @ 30 mW/cm2 Initial Initial Final FinalSample CCT Initial EQE Irradiation CCT Final EQE Label (K) CRI (%) Time,Hrs (K) CRI (%) A 2649 86.5 62  1 2482 87.1 78 B 2664 85.6 — 13 2519 8782 C 2609 85.6 65  2 2444 87.1 77 D 2641 85.4 62  10 * 2472 87.2 80 E2659 85.2 63 11 2480 87.3 80 F 2684 84.5 60 11 2446 87.3 80 * 2 hrs 50C. @ 30 mW/cm2 450 nm, 8 hrs 50 C. @ 15 mW/cm2 450 nm

Because semiconductor nanocrystals have narrow emission linewidths, arephotoluminescent efficient, and emission wavelength tunable with thesize and/or composition of the nanocrystals, they are preferred quantumconfined semiconductor nanoparticles for use in the various aspects andembodiments of the inventions described herein.

The size and composition of quantum confined semiconductor nanoparticles(including, e.g., semiconductor nanocrystals) useful in the variousaspects and embodiments of the inventions can be selected such thatsemiconductor nanocrystals emit photons at a predetermined wavelength ofwavelength band in the far-visible, visible, infra-red or other desiredportion of the spectrum. For example, the wavelength can be between 300and 2,500 nm or greater, such as between 300 and 400 nm, between 400 and700 nm, between 700 and 1100 nm, between 1100 and 2500 nm, or greaterthan 2500 nm.

Quantum confined semiconductor nanoparticles (including, e.g.,semiconductor nanocrystals) are nanometer-scale inorganic semiconductornanoparticles. Semiconductor nanocrystals include, for example,inorganic crystallites between about 1 nm and about 1000 nm in diameter,preferably between about 2 nm and about 50 um, more preferably about 1nm to about 20 nm (such as about 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, or 20 nm).

Semiconductor nanocrystals included in various aspect and embodiments ofthe inventions most preferably have an average nanocrystal diameter lessthan about 150 Angstroms (Å). In certain embodiments, semiconductornanocrystals having an average nanocrystal diameter in a range fromabout 12 to about 150 Å can be particularly desirable.

However, depending upon the composition and desired emission wavelengthof the semiconductor nanocrystal, the average diameter may be outside ofthese various preferred size ranges.

The semiconductor forming the nanoparticles and nanocrystals for use inthe various aspects and embodiments of the inventions described hereincan comprise Group IV elements, Group II-VI compounds, Group II-Vcompounds, Group III-VI compounds, Group III-V compounds, Group IV-VIcompounds, Group compounds, Group II-IV-VI compounds, or Group II-IV-Vcompounds, for example, CdS, CdO, CdSe, CdTe, ZnS, ZnO, ZnSe, ZnTe,MgTe, GaAs, GaP, GaSb, GaN, HgS, HgO, HgSe, HgTe, InAs, InP, InSb, InN,AlAs, AlP, AlSb, AlS, PbS, PbO, PbSe, Ge, Si, alloys thereof, and/ormixtures thereof, including ternary and quaternary mixtures and/oralloys.

Examples of the shape of the nanoparticles and nanocrystals includesphere, rod, disk, other shape or mixtures thereof.

In certain preferred aspects and embodiments of the inventions, quantumconfined semiconductor nanoparticles (including, e.g., semiconductornanocrystals) include a “core” of one or more first semiconductormaterials, which may include an overcoating or “shell” of a secondsemiconductor material on at least a portion of a surface of the core.In certain embodiments, the shell surrounds the core. A quantum confinedsemiconductor nanoparticle (including, e.g., semiconductor nanocrystal)core including a shell on at least a portion of a surface of the core isalso referred to as a “core/shell” semiconductor nanocrystal.

For example, a quantum confined semiconductor nanoparticle (including,e.g., semiconductor nanocrystal) can include a core comprising a GroupIV element or a compound represented by the formula MX, where M iscadmium, zinc, magnesium, mercury, aluminum, gallium, indium, thallium,or mixtures thereof, and X is oxygen, sulfur, selenium, tellurium,nitrogen, phosphorus, arsenic, antimony, or mixtures thereof. Examplesof materials suitable for use as a core include, but are not limited to,CdS, CdO, CdSe, CdTe, ZnS, ZnO, ZnSe, ZnTe, MgTe, GaAs, GaP, GaSb, GaN,HgS, HgO, HgSe, HgTe, InAs, InP, InSb, InN, AlAs, AlP, AlSb, AlS, PbS,PbO, PbSe, Ge, Si, alloys thereof, and/or mixtures thereof, includingternary and quaternary mixtures and/or alloys. Examples of materialssuitable for use as a shell include, but are not limited to, CdS, CdO,CdSe, CdTe, ZnS, ZnO, ZnSe, ZnTe, MgTe, GaAs, GaP, GaSb, GaN, HgS, HgO,HgSe, HgTe, InAs, InP, InSb, InN, AlAs, AlP, AlSb, AlS, PbS, PbO, PbSe,Ge, Si, alloys thereof, and/or mixtures thereof, including ternary andquaternary mixtures and/or alloys.

In certain embodiments, the surrounding “shell” material can have abandgap greater than the bandgap of the core material and can be chosenso as to have an atomic spacing close to that of the “core” substrate.In another embodiment, the surrounding shell material can have a bandgapless than the bandgap of the core material. In a further embodiment, theshell and core materials can have the same crystal structure. Shellmaterials are discussed further below. For further examples ofcore/shell semiconductor structures, see U.S. application Ser. No.10/638,546, entitled “Semiconductor Nanocrystal Heterostructures”, filed12 Aug. 2003, which is hereby incorporated herein by reference in itsentirety.

Quantum confined semiconductor nanoparticles are preferably members of apopulation of semiconductor nanoparticles having a narrow sizedistribution. More preferably, the quantum confined semiconductornanoparticles (including, e.g., semiconductor nanocrystals) comprise amonodisperse or substantially monodisperse population of nanoparticles.

Quantum confined semiconductor nanoparticles show strong quantumconfinement effects that can be harnessed in designing bottom-upchemical approaches to create optical properties that are tunable withthe size and composition of the nanoparticles.

For example, preparation and manipulation of semiconductor nanocrystalsare described in Murray et al. (J. Am. Chem. Soc., 115:8706 (1993)); inthe thesis of Christopher Murray, “Synthesis and Characterization ofII-VI Quantum Dots and Their Assembly into 3-D Quantum DotSuperlattices”, Massachusetts Institute of Technology, September, 1995;and in U.S. patent application Ser. No. 08/969,302 entitled “HighlyLuminescent Color-selective Materials” which are hereby incorporatedherein by reference in their entireties. Other examples of thepreparation and manipulation of semiconductor nanocrystals are describedin U.S. Pat. Nos. 6,322,901 and 6,576,291, and U.S. Patent ApplicationNo. 60/550,314, each of which is hereby incorporated herein by referencein its entirety.

Other materials, techniques, methods, applications, and information thatmay be useful with the present invention are described in U.S. patentapplication Ser. No. 11/354,185 of Bawendi et al., entitled “LightEmitting Devices Including Semiconductor Nanocrystals”, filed 15 Feb.2006; U.S. patent application Ser. No. 11/253,595 of Coe-Sullivan etal., entitled “Light Emitting Device Including SemiconductorNanocrystals”, filed 21 Oct. 2005; U.S. patent application Ser. No.10/638,546 of Kim et al., entitled “Semiconductor NanocrystalHeterostructures”, filed 12 Aug. 2003, referred to above; Murray, etal., J. Am. Chem. Soc., Vol. 115, 8706 (1993); Kortan, et al., J. Am.Chem. Soc., Vol. 112, 1327 (1990); and the Thesis of Christopher Murray,“Synthesis and Characterization of II-VI Quantum Dots and Their Assemblyinto 3-D Quantum Dot Superlattices”, Massachusetts Institute ofTechnology, September, 1995, U.S. Application No. 60/971,887 of Breen,et al., for “Functionalized Semiconductor Nanocrystals And Method”,filed 12 Sep. 2007, U.S. Application No. 60/866,822 of Clough, et al.,for “Nanocrystals Including A Group IIIA Element And A Group VA Element,Method, Composition, Device and Other Products”, filed 21 Nov. 2006;U.S. Provisional Patent Application No. 60/866,828 of Craig Breen etal., for “Semiconductor Nanocrystal Materials And Compositions AndDevices Including Same,” filed 21 Nov. 2006; U.S. Provisional PatentApplication No. 60/866,832 of Craig Breen et al. for “SemiconductorNanocrystal Materials And Compositions And Devices Including Same,”filed 21 Nov. 2006; U.S. Provisional Patent Application No. 60/866,833of Dorai Ramprasad for “Semiconductor Nanocrystal And Compositions AndDevices Including Same” filed 21 Nov. 2006; U.S. Provisional PatentApplication No. 60/866,834 of Dorai Ramprasad for “SemiconductorNanocrystal And Compositions And Devices Including Same,” filed 21 Nov.2006; U.S. Provisional Patent Application No. 60/866,839 of DoraiRamprasad for “Semiconductor Nanocrystal And Compositions And DevicesIncluding Same” filed 21 Nov. 2006; U.S. Provisional Patent ApplicationNo. 60/866,843 of Dorai Ramprasad for “Semiconductor Nanocrystal AndCompositions And Devices Including Same,” filed 21 Nov. 2006, and U.S.Patent Application No. 60/050,929 of Seth Coe-Sullivan et al. for“Optical Components, Systems Including an Optical Component, AndDevices”, filed 6 May 2008. Each of the foregoing is hereby incorporatedby reference herein in its entirety.

In various aspects and embodiments of the invention, quantum confinedsemiconductor nanoparticles (including, but not limited to,semiconductor nanocrystals) optionally have ligands attached thereto.

In certain embodiments, the ligands are derived from the coordinatingsolvent used during the growth process. The surface can be modified byrepeated exposure to an excess of a competing coordinating group to forman overlayer. For example, a dispersion of the capped semiconductornanocrystal can be treated with a coordinating organic compound, such aspyridine, to produce crystallites which disperse readily in pyridine,methanol, and aromatics but no longer disperse in aliphatic solvents.Such a surface exchange process can be carried out with any compoundcapable of coordinating to or bonding with the outer surface of thesemiconductor nanocrystal, including, for example, phosphines, thiols,amines and phosphates. The semiconductor nanocrystal can be exposed toshort chain polymers which exhibit an affinity for the surface and whichterminate in a moiety having an affinity for a suspension or dispersionmedium. Such affinity improves the stability of the suspension anddiscourages flocculation of the semiconductor nanocrystal. In otherembodiments, semiconductor nanocrystals can alternatively be preparedwith use of non-coordinating solvent(s).

For example, a coordinating ligand can have the formula:(Y—)_(k-n)—(X)-(-L)_(n)wherein k is 2, 3 or 5, and n is 1, 2, 3, 4 or 5 such that k-n is notless than zero; X is O, S, S═O, SO2, Se, Se═O, N, N═O, P, P═O, As, orAs═O; each of Y and L, independently, is aryl, heteroaryl, or a straightor branched C2-12 hydrocarbon chain optionally containing at least onedouble bond, at least one triple bond, or at least one double bond andone triple bond. The hydrocarbon chain can be optionally substitutedwith one or more C1-4 alkyl, C2-4 alkenyl, C2-4 alkynyl, C1-4 alkoxy,hydroxyl, halo, amino, nitro, cyano, C3-5 cycloalkyl, 3-5 memberedheterocycloalkyl, aryl, heteroaryl, C1-4 alkylcarbonyloxy, C1-4alkyloxycarbonyl, C1-4 alkylcarbonyl, or formyl. The hydrocarbon chaincan also be optionally interrupted by —O—, —S—, —N(Ra)—, —N(Ra)—C(O)—O—,—O—C(O)—N(Ra)—, —N(Ra)—C(O)—N(Rb)—, —O—C(O)—O—, —P(Ra)—, or —P(O)(Ra)—.Each of Ra and Rb, independently, is hydrogen, alkyl, alkenyl, alkynyl,alkoxy, hydroxylalkyl, hydroxyl, or haloalkyl. An aryl group is asubstituted or unsubstituted cyclic aromatic group. Examples includephenyl, benzyl, naphthyl, tolyl, anthracyl, nitrophenyl, or halophenyl.A heteroaryl group is an aryl group with one or more heteroatoms in thering, for instance furyl, pyiridyl, pyrrolyl, phenanthiyl.

A suitable coordinating ligand can be purchased commercially or preparedby ordinary synthetic organic techniques, for example, as described inJ. March, Advanced Organic Chemistry, which is incorporated herein byreference in its entirety.

See also U.S. patent application Ser. No. 10/641,292 entitled“Stabilized Semiconductor Nanocrystals”, filed 15 Aug. 2003, which ishereby incorporated herein by reference in its entirety.

When an electron and hole localize on a quantum confined semiconductornanoparticle (including, but not limited to, a semiconductornanocrystal), emission can occur at an emission wavelength. The emissionhas a frequency that corresponds to the band gap of the quantum confinedsemiconductor material. The band gap is a function of the size of thenanoparticle. Quantum confined semiconductor nanoparticle s having smalldiameters can have properties intermediate between molecular and bulkforms of matter. For example, quantum confined semiconductornanoparticles having small diameters can exhibit quantum confinement ofboth the electron and hole in all three dimensions, which leads to anincrease in the effective band gap of the material with decreasingcrystallite size. Consequently, for example, both the optical absorptionand emission of semiconductor nanocrystals shift to the blue, or tohigher energies, as the size of the crystallites decreases.

For an example of blue light-emitting semiconductor nanocrystalmaterials, see U.S. patent application Ser. No. 11/071,244, filed 4 Mar.2005, which is hereby incorporated by reference herein in its entirety.

The emission from a quantum confined semiconductor nanoparticle can be anarrow Gaussian emission band that can be tuned through the completewavelength range of the ultraviolet, visible, or infra-red regions ofthe spectrum by varying the size of the quantum confined semiconductornanoparticle, the composition of the quantum confined semiconductornanoparticle, or both. For example, CdSe can be tuned in the visibleregion and InAs can be tuned in the infra-red region. The narrow sizedistribution of a population of quantum confined semiconductornanoparticles can result in emission of light in a narrow spectralrange. The population can be monodisperse preferably exhibits less thana 15% rms (root-mean-square) deviation in diameter of the quantumconfined semiconductor nanoparticle s, more preferably less than 10%,most preferably less than 5%. Spectral emissions in a narrow range of nogreater than about 75 nm, preferably 60 nm, more preferably 40 nm, andmost preferably 30 nm full width at half max (FWHM) for quantum confinedsemiconductor nanoparticle s that emit in the visible can be observed.IR-emitting quantum confined semiconductor nanoparticle s can have aFWHM of no greater than 150 nm, or no greater than 100 nm. Expressed interms of the energy of the emission, the emission can have a FWHM of nogreater than 0.05 eV, or no greater than 0.03 eV. The breadth of theemission decreases as the dispersity of quantum confined semiconductornanoparticle diameters decreases.

For example, semiconductor nanocrystals can have high emission quantumefficiencies such as greater than 10%, 20%, 30%, 40%, 50%, 60%, 70%,80%, or 90%.

The narrow FWHM of semiconductor nanocrystals can result in saturatedcolor emission. The broadly tunable, saturated color emission over theentire visible spectrum of a single material system is unmatched by anyclass of organic chromophores (see, for example, Dabbousi et al., J.Phys. Chem. 101, 9463 (1997), which is incorporated by reference in itsentirety). A monodisperse population of semiconductor nanocrystals willemit light spanning a narrow range of wavelengths. A pattern includingmore than one size of semiconductor nanocrystal can emit light in morethan one narrow range of wavelengths. The color of emitted lightperceived by a viewer can be controlled by selecting appropriatecombinations of semiconductor nanocrystal sizes and materials. Thedegeneracy of the band edge energy levels of semiconductor nanocrystalsfacilitates capture and radiative recombination of all possibleexcitons.

Transmission electron microscopy (TEM) can provide information about thesize, shape, and distribution of the semiconductor nanocrystalpopulation. Powder X-ray diffraction (XRD) patterns can provide the mostcomplete information regarding the type and quality of the crystalstructure of the semiconductor nanocrystals. Estimates of size are alsopossible since particle diameter is inversely related, via the X-raycoherence length, to the peak width. For example, the diameter of thesemiconductor nanocrystal can be measured directly by transmissionelectron microscopy or estimated from X-ray diffraction data using, forexample, the Scherrer equation. It also can be estimated from the UV/Visabsorption spectrum.

Quantum confined semiconductor nanoparticles are preferably handled in acontrolled (oxygen-free and moisture-free) environment, preventing thequenching of luminescent efficiency during the fabrication process.

An optical material comprising 1 quantum confined semiconductornanoparticles can be dispersed in a liquid medium and are thereforecompatible with thin-film deposition techniques such as spin-casting,drop-casting, and dip coating.

In certain preferred embodiments, an optical material for use in variousaspects and embodiments in accordance with the invention can beprepared, for example, from an ink comprising quantum confinedsemiconductor nanoparticles and a liquid vehicle, wherein the liquidvehicle comprises one or more functional groups that are capable ofbeing polymerized (e.g., cross-linked) to form a host material. Incertain embodiments, the functional units can be cross-linked by UVtreatment. In certain embodiments, the functional units can becross-linked by thermal treatment. In certain embodiments, thefunctional units can be cross-linked by other cross-linking techniquereadily ascertainable by a person of ordinary skill in a relevant art.In certain embodiments, the optical material including one or morefunctional groups that are capable of being cross-linked can be theliquid vehicle itself. See also U.S. Application No. 60/946,090 ofLinton, et al., for “Methods For Depositing Nanomaterial, Methods ForFabricating A Device, Methods For Fabricating An Array Of Devices AndCompositions”, filed 25 Jun. 2007, and U.S. Application No. 60/949,306of Linton, et al., for “Compositions, Methods For DepositingNanomaterial, Methods For Fabricating A Device, And Methods ForFabricating An Array Of Devices”, filed 12 Jul. 2007, the disclosures ofeach of which are hereby incorporated herein by reference. Optionally,the ink further includes scatterers and/or other additives.

An ink can be deposited onto a surface of a substrate by printing,screen-printing, spin-coating, gravure techniques, inkjet printing, rollprinting, etc. The ink can be deposited in a predetermined arrangement.For example, the ink can be deposited in a patterned or unpatternedarrangement. For additional information that may be useful to deposit anink onto a substrate, see for example, International Patent ApplicationNo. PCT/US2007/014711, entitled “Methods For Depositing Nanomaterial,Methods For Fabricating A Device, And Methods For Fabricating An ArrayOf Devices”, of Seth A. Coe-Sullivan, filed 25 Jun. 2007, InternationalPatent Application No. PCT/US2007/014705, entitled “Methods ForDepositing Nanomaterial, Methods For Fabricating A Device, Methods ForFabricating An Array Of Devices And Compositions”, of Seth A.Coe-Sullivan, et al., filed 25 Jun. 2007, International PatentApplication No. PCT/US2007/014706, entitled “Methods And ArticlesIncluding Nanomaterial”, of Seth A. Coe-Sullivan, et al., filed 25 Jun.2007, International Patent Application No. PCT/US2007/08873, entitled“Composition Including Material, Methods Of Depositing Material,Articles Including Same And Systems For Depositing Material”, of Seth A.Coe-Sullivan, et al., filed 9 Apr. 2007, International PatentApplication No. PCT/US2007/09255, entitled “Methods Of DepositingMaterial, Methods Of Making A Device, And Systems And Articles For UseIn Depositing Material”, of Maria J, Anc, et al., filed 13 Apr. 2007,International Patent Application No. PCT/US2007/08705, entitled “MethodsAnd Articles Including Nanomaterial”, of Seth Coe-Sullivan, et al, filed9 Apr. 2007, International Patent Application No. PCT/US2007/08721,entitled “Methods Of Depositing Nanomaterial & Methods Of Making ADevice” of Marshall Cox, et al., filed 9 Apr. 2007, U.S. patentapplication Ser. Nos. 11/253,612, entitled “Method And System ForTransferring A Patterned Material” of Seth Coe-Sullivan, et al., filed20 Oct. 2005, and U.S. patent application Ser. No. 11/253,595, entitled“Light Emitting Device Including Semiconductor Nanocrystals”, of SethCoe-Sullivan, et al., filed 20 Oct. 2005, each of the foregoing patentapplications being hereby incorporated herein by reference.

Due to the positioning of the optical material comprising quantumconfined semiconductor nanoparticles in features or layers resultingfrom these deposition techniques, not all of the surfaces of thenanoparticles may be available to absorb and emit light.

In certain embodiments, an optical material comprising quantum confinedsemiconductor nanoparticles can be deposited on a surface using contactprinting. See, for example, A. Kumar and G. Whitesides, Applied PhysicsLetters, 63, 2002-2004, (1993); and V. Santhanam and R. P. Andres, NanoLetters, 4, 41-44, (2004), each of which is incorporated by reference inits entirety. See also U.S. patent application Ser. No. 11/253,612,filed 21 Oct. 2005, entitled “Method And System For Transferring APatterned Material”, of Coe-Sullivan et al. and U.S. patent applicationSer. No. 11/253,595, filed 21 Oct. 2005, entitled “Light Emitting DeviceIncluding Semiconductor Nanocrystals,” of Coe-Sullivan, each of which isincorporated herein by reference in its entirety.

This technique can be use for depositing a various thicknesses ofoptical materials comprising quantum confined semiconductornanoparticles. In certain embodiments the thickness is selected toachieve the desired % absorption thereby. Most preferably, the quantumconfined semiconductor nanoparticles do not absorb any, or absorb onlynegligible amounts of, the re-emitted photons.

In certain embodiments, methods for applying a material (e.g., anoptical material) to a predefined region on a substrate (e.g., supportelement) may be desirable. The predefined region is a region on thesubstrate where the material is selectively applied. In certainembodiments wherein the optical component includes one or more differenttypes of quantum confined semiconductor nanoparticles to compensate formore than one spectral deficiency of a light source, different types ofquantum confined semiconductor nanoparticle can optionally be includedin one or more different optical materials. In certain embodimentswherein the optical component includes one or more different types ofquantum confined semiconductor nanoparticles to compensate for more thanone spectral deficiency of a light source, different types of quantumconfined semiconductor nanoparticle can optionally be included in two ormore different optical materials, and each of the different opticalmaterials can be applied to different regions of the substrate and/or asseparate layers over the substrate. The material and substrate can bechosen such that the material remains substantially entirely within thepredetermined area. By selecting a predefined region that forms apattern, material can be applied to the substrate such that the materialforms a pattern. The pattern can be a regular pattern (such as an array,or a series of lines), or an irregular pattern. Once a pattern ofmaterial is formed on the substrate, the substrate can have a regionincluding the material (the predefined region) and a regionsubstantially free of material. In some circumstances, the materialforms a monolayer on the substrate. The predefined region can be adiscontinuous region. In other words, when the material is applied tothe predefined region of the substrate, locations including the materialcan be separated by other locations that are substantially free of thematerial.

An optical material comprising quantum confined semiconductornanoparticles can alternatively be deposited by solution basedprocessing techniques, phase-separation, spin casting, inkjet printing,silk-screening, and other liquid film techniques available for formingpatterns on a surface.

Alternatively, quantum confined semiconductor nanoparticles can bedispersed in a light-transmissive host material (e.g., a polymer, aresin, a silica glass, or a silica gel, etc., which is preferably atleast partially light-transmissive, and more preferably transparent, tothe light emitted by the quantum confined semiconductor nanoparticlesand in which quantum confined semiconductor nanoparticles can bedispersed) that is deposited as a full or partial layer or in apatterned arrangement by any of the above-listed or other knowntechniques. Suitable materials include many inexpensive and commonlyavailable materials, such as polystyrene, epoxy, polyimides, and silicaglass. After application to the surface, such material may contain adispersion of quantum confined semiconductor nanoparticles where thenanoparticles have been size selected so as to produce light of a givencolor. Other configurations of quantum confined semiconductornanoparticles disposed in a material, such as, for example, atwo-dimensional layer on a substrate with a polymer overcoating are alsocontemplated.

U.S. Patent Application No. 61/016,227 of Seth Coe-Sullivan et al. for“Compositions, Optical Component, System Including An OpticalComponents, and Devices”, filed 21 Dec. 2007 is hereby incorporatedherein by reference in its entirety.

As used herein, “top”, “bottom”, “over”, and “under” are relativepositional terms, based upon a location from a reference point. Moreparticularly, “top” means farthest away from a reference point, while“bottom” means closest to the reference point. Where, e.g., a layer isdescribed as disposed or deposited “over” a component or substrate, thelayer is disposed farther away from the component or substrate. Theremay be other layers between the layer and component or substrate. Asused herein, “cover” is also a relative position term, based upon alocation from a reference point. For example, where a first material isdescribed as covering a second material, the first material is disposedover, but not necessarily in contact with the second material.

As used herein, the singular forms “a”, “an” and “the” include pluralunless the context clearly dictates otherwise. Thus, for example,reference to an emissive material includes reference to one or more ofsuch materials.

Applicants specifically incorporate the entire contents of all citedreferences in this disclosure. Further, when an amount, concentration,or other value or parameter is given as either a range, preferred range,or a list of upper preferable values and lower preferable values, thisis to be understood as specifically disclosing all ranges formed fromany pair of any upper range limit or preferred value and any lower rangelimit or preferred value, regardless of whether ranges are separatelydisclosed. Where a range of numerical values is recited herein, unlessotherwise stated, the range is intended to include the endpointsthereof, and all integers and fractions within the range. It is notintended that the scope of the invention be limited to the specificvalues recited when defining a range.

Other embodiments of the present invention will be apparent to thoseskilled in the art from consideration of the present specification andpractice of the present invention disclosed herein. It is intended thatthe present specification and examples be considered as exemplary onlywith a true scope and spirit of the invention being indicated by thefollowing claims and equivalents thereof.

The invention claimed is:
 1. A solid state lighting device comprising aphosphor converted LED light source that emits white light including ablue spectral component and having a deficiency in at least one spectralregion, and an optical component that is positioned to receive at leasta portion of the white light generated by the light source andsupplement the spectrum of the white light passing through the opticalcomponent, the optical component comprising an optical material forconverting at least a portion of the blue spectral component of thewhite light to one or more predetermined wavelengths such that lightemitted by the solid state lighting device includes white light emissionfrom the light source supplemented with light emission at one or morepredetermined wavelengths in a deficient spectral region of the lightsource, wherein the optical material comprises quantum confinedsemiconductor nanoparticles distributed in a host material, wherein theoptical material is fully encapsulated by one or more barrier materials,and wherein the optical component is not in direct contact with thelight source.
 2. A solid state lighting device in accordance with claim1 wherein at least one predetermined wavelength is in a range from about575 nm to about 650 nm.
 3. A solid state lighting device in accordancewith claim 1 wherein at least one predetermined wavelength is in a rangefrom about 450 nm to about 500 nm.
 4. A solid state lighting device inaccordance with claim 1 wherein the light emitted by the light sourcehas a General Color Rendering Index (R_(a)) less than
 80. 5. A solidstate lighting device in accordance with claim 4 wherein the lightemitted by the solid state lighting device has a General Color RenderingIndex (R_(a)) greater than
 80. 6. A solid state lighting device inaccordance with claim 4 wherein the light emitted by the solid statelighting device has a General Color Rendering Index (R_(a)) greater than85.
 7. A solid state lighting device in accordance with claim 4 whereinthe light emitted by the solid state lighting device has a General ColorRendering Index (R_(a)) greater than
 90. 8. A solid state lightingdevice in accordance with claim 4 wherein the light emitted by the solidstate lighting device has a General Color Rendering Index (R_(a))greater than
 95. 9. A solid state lighting device in accordance withclaim 1 wherein the General Color Rendering Index (R_(a)) of the lightemitted by the solid state lighting device is at least 10% higher thanthe General Color Rendering Index (R_(a)) of the light emitted by thelight source.
 10. A solid state lighting device in accordance with claim1 wherein the solid state lighting device maintains greater than 70% ofthe light source lumens per watt efficiency.
 11. A solid state lightingdevice in accordance with claim 1 wherein the solid state lightingdevice maintains greater than 100% of the light source lumens per wattefficiency.
 12. A solid state lighting device in accordance with claim 1wherein the solid state lighting device maintains greater than 110% ofthe light source lumens per watt efficiency.
 13. A solid state lightingdevice in accordance with claim 1 wherein the lumens per watt efficiencyof the solid state lighting device does not substantially vary as afunction of the color temperature of the solid state lighting device.14. A solid state lighting device in accordance with claim 1 whereinquantum confined semiconductor nanoparticles are included in the opticalmaterial in an amount in a range from about 0.001 to about 5 weightpercent of the weight of the host material.
 15. A solid state lightingdevice in accordance with claim 1 wherein the optical material furthercomprises light scatterers.
 16. A solid state lighting device inaccordance with claim 15 wherein light scattering particles are includedin the optical material in an amount in a range from about 0.001 toabout 5 weight percent of the weight of the host material.
 17. A solidstate lighting device in accordance with claim 1 wherein the opticalcomponent further includes a support element and the optical materialcomprising quantum confined semiconductor nanoparticles is disposed overa surface of the support element.
 18. A solid state lighting device inaccordance with claim 17 wherein the support element is opticallytransparent to the light output from the solid state lighting device.19. A solid state lighting device in accordance with claim 17 whereinthe support element comprises a cover plate for the solid state lightingdevice.
 20. A solid state lighting device in accordance with claim 1wherein the temperature at the location of the nanoparticles duringoperation of the solid state lighting device is less than 90° C.
 21. Asolid state lighting device in accordance with claim 1 wherein the lightsource comprises a blue light emitting semiconductor LED including aphosphor material for converting the blue LED light output to whitelight.
 22. A solid state lighting device in accordance with claim 21wherein optical material comprises quantum confined semiconductornanoparticles capable of emitting red light.
 23. A solid state lightingdevice in accordance with claim 1 wherein the optical material comprisesquantum confined semiconductor nanoparticles capable of emitting redlight.
 24. A solid state lighting device in accordance with claim 1wherein the quantum confined semiconductor nanoparticles comprise asemiconductor nanocrystal including a core comprising a semiconductormaterial and an inorganic shell disposed on at least a portion of asurface of the core.
 25. A solid state lighting device in accordancewith claim 1 wherein the light emitted from the solid state lightingdevice has a correlated color temperature that is at least about 1000Kless than that of light emitted from the light source.
 26. A solid statelighting device in accordance with claim 1 wherein the light emittedfrom the solid state lighting device has a correlated color temperaturethat is at least about 2000K less than that of light emitted from thelight source.
 27. A solid state lighting device in accordance with claim1 wherein the light emitted from the solid state lighting device has acorrelated color temperature that is at least about 3000K less than thatof light emitted from the light source.
 28. A solid state lightingdevice in accordance with claim 1 wherein the light emitted from thesolid state lighting device has a correlated color temperature that isat least about 4000K less than that of light emitted from the lightsource.
 29. A solid state lighting device in accordance with claim 1wherein the optical component comprises two or more different types ofquantum confined semiconductor nanoparticles, wherein each differenttype of quantum confined semiconductor nanoparticles emits light atpredetermined wavelength that is different from the predeterminedwavelength emitted by at least one of another type of quantum confinedsemiconductor nanoparticles included in the optical material, andwherein two or more different predetermined wavelengths are selectedsuch that the optical material will compensate for two or more spectraldeficiencies of the light source.
 30. A solid state lighting device inaccordance with claim 1 wherein the optical component is fullyencapsulated.
 31. A solid state lighting device comprising a phosphorconverted LED light source that emits white light including emission inthe blue spectral region and having a deficiency in the orange to redspectral region; and an optical component that is positioned to receiveand supplement the spectrum of white light emitted by the LED andpassing through the optical component, the optical component comprisingan optical material for converting at least a portion of the emission inthe blue spectral region to light in the spectral region with awavelength in a range from about 575 nm to about 650 nm such that lightemitted by the solid state lighting device includes white light emissionfrom the LED light source supplemented with converted light emission,wherein the optical material comprises quantum confined semiconductornanoparticles and light scatterers distributed in a host material,wherein the optical material is fully encapsulated by one or morebarrier materials, and wherein the optical component is not in directcontact with the light source.
 32. A solid state lighting device inaccordance with claim 31 wherein the quantum confined semiconductornanoparticles comprise a semiconductor nanocrystal including a corecomprising a semiconductor material and an inorganic shell disposed onat least a portion of a surface of the core.
 33. An optical componentfor use with a light source that emits white light including a bluespectral component and at least one spectral deficiency in anotherregion of the spectrum of the white light emitted by the light source,the optical component comprising an optically transparent substratecomprising a diffuser and an optical material for converting at least aportion of the blue spectral component of white light output from thelight source passing through the optical component to one or morepredetermined wavelengths, wherein the optical material comprisesquantum confined semiconductor nanoparticles and light scatterersdistributed in a host material, wherein the optical material is disposedover a surface of the optically transparent substrate, and wherein theoptical material is fully encapsulated by one or more barrier materials.34. An optical component in accordance with claim 33 wherein one or moreof the predetermined wavelengths is selected to compensate for thedeficiency in the spectral region of the white light emitting source.35. An optical component in accordance with claim 33 wherein one or moreof the predetermined wavelengths are in a range from about 575 nm to 650nm.
 36. An optical component in accordance with claim 33 wherein thelight source emits white light with a spectral deficiency in the cyanspectral region and the predetermined wavelength can be in a range fromabout 450 nm to about 500 nm.
 37. An optical component in accordancewith claim 33 wherein the optical component comprises two or moredifferent types of quantum confined semiconductor nanoparticles, whereineach different type of quantum confined semiconductor nanoparticlesemits light at predetermined wavelength that is different from thepredetermined wavelength emitted by at least one of another type ofquantum confined semiconductor nanoparticles included in the opticalmaterial, and wherein two or more different predetermined wavelengthsare selected such that the optical material will compensate for one ormore spectral deficiencies of the white light emitting source.
 38. Anoptical component in accordance with claim 33 wherein the opticalcomponent includes two or more different types of quantum confinedsemiconductor nanoparticles that emit at different predeterminedwavelengths, wherein the different types of quantum confinedsemiconductor nanoparticles are included in two or more differentoptical materials.
 39. An optical component in accordance with claim 33wherein the quantum confined semiconductor nanoparticles have a solidstate quantum efficiency of at least 40%.
 40. An optical component inaccordance with claim 33 wherein the quantum confined semiconductornanoparticles maintain at least 40% efficiency during use of the opticalcomponent.
 41. An optical component in accordance with claim 33 whereinthe optical component is fully encapsulated.